human mind experiments

The 11 Most Influential Psychological Experiments in History

The history of psychology is marked by groundbreaking experiments that transformed our understanding of the human mind. These 11 Most Influential Psychological Experiments in History stand out as pivotal, offering profound insights into behaviour, cognition, and the complexities of human nature.

In this PsychologyOrg article, we’ll explain these key experiments, exploring their impact on our understanding of human behaviour and the intricate workings of the mind.

Table of Contents

Experimental psychology.

Experimental psychology is a branch of psychology that uses scientific methods to study human behaviour and mental processes. Researchers in this field design experiments to test hypotheses about topics such as perception, learning, memory, emotion, and motivation.

They use a variety of techniques to measure and analyze behaviour and mental processes, including behavioural observations, self-report measures, physiological recordings, and computer simulations. The findings of experimental psychology studies can have important implications for a wide range of fields, including education, healthcare, and public policy.

Experimental Psychology, Psychologists have long tried to gain insight into how we perceive the world, to understand what motivates our behavior. They have made great strides in lifting that veil of mystery. In addition to providing us with food for stimulating party conversations, some of the most famous psychological experiments of the last century reveal surprising and universal truths about nature.

Throughout the history of psychology, revolutionary experiments have reshaped our comprehension of the human mind. These 11 experiments are pivotal, providing deep insights into human behaviour, cognition, and the intricate facets of human nature.

1. Kohler and the Chimpanzee experiment

Wolfgang Kohler studied the insight process by observing the behaviour of chimpanzees in a problem situation. In the experimental situation, the animals were placed in a cage outside of which food, for example, a banana, was stored. There were other objects in the cage, such as sticks or boxes. The animals participating in the experiment were hungry, so they needed to get to the food. At first, the chimpanzee used sticks mainly for playful activities; but suddenly, in the mind of the hungry chimpanzee, a relationship between sticks and food developed.

The cane, from an object to play with, became an instrument through which it was possible to reach the banana placed outside the cage. There has been a restructuring of the perceptual field: Kohler stressed that the appearance of the new behaviour was not the result of random attempts according to a process of trial and error. It is one of the first experiments on the intelligence of chimpanzees.

2. Harlow’s experiment on attachment with monkeys

In a scientific paper (1959), Harry F. Harlow described how he had separated baby rhesus monkeys from their mothers at birth, and raised them with the help of “puppet mothers”: in a series of experiments he compared the behavior of monkeys in two situations:

Little monkeys with a puppet mother without a bottle, but covered in a soft, fluffy, and furry fabric. Little monkeys with a “puppet” mother that supplied food, but was covered in wire. The little monkeys showed a clear preference for the “furry” mother, spending an average of fifteen hours a day attached to her, even though they were exclusively fed by the “suckling” puppet mother. conclusions of the Harlow experiment: all the experiments showed that the pleasure of contact elicited attachment behaviours, but the food did not.

3. The Strange Situation by Mary Ainsworth

Building on Bowlby’s attachment theory, Mary Ainsworth and colleagues (1978) have developed an experimental method called the Strange Situation, to assess individual differences in attachment security. The Strange Situation includes a series of short laboratory episodes in a comfortable environment and the child’s behaviors are observed.

Ainsworth and colleagues have paid special attention to the child’s behaviour at the time of reunion with the caregiver after a brief separation, thus identifying three different attachment patterns or styles, so called from that moment on. kinds of attachment according to Mary Ainsworth:

Secure attachment (63% of the dyads examined) Anxious-resistant or ambivalent (16%) Avoidant (21%) The Strange Situation by Mary Ainsworth

In a famous 1971 experiment, known as the Stanford Prison, Zimbardo and a team of collaborators reproduced a prison in the garages of Stanford University to study the behaviour of subjects in a context of very particular and complex dynamics. Let’s see how it went and the thoughts on the Stanford prison experiment. The participants (24 students) were randomly divided into two groups:

“ Prisoners “. The latter were locked up in three cells in the basement of a University building for six days; they were required to wear a white robe with a paper over it and a chain on the right ankle. “ Guards “. The students who had the role of prison guards had to watch the basement, choose the most appropriate methods to maintain order, and make the “prisoners” perform various tasks; they were asked to wear dark glasses and uniforms, and never to be violent towards the participants of the opposite role. However, the situation deteriorated dramatically: the fake police officers very soon began to seriously mistreat and humiliate the “detainees”, so it was decided to discontinue the experiment.

4. Jane Elliot’s Blue Eyes Experiment

On April 5, 1968, in a small school in Riceville, Iowa, Professor Jane Elliot decided to give a practical lesson on racism to 28 children of about eight years of age through the blue eyes brown eyes experiment.

“Children with brown eyes are the best,” the instructor began. “They are more beautiful and intelligent.” She wrote the word “melanin” on the board and explained that it was a substance that made people intelligent. Dark-eyed children have more, so they are more intelligent, while blue-eyed children “go hand in hand.”

In a very short time, the brown-eyed children began to treat their blue-eyed classmates with superiority, who in turn lost their self-confidence. A very good girl started making mistakes during arithmetic class, and at recess, she was approached by three little friends with brown eyes “You have to apologize because you get in their way and because we are the best,” said one of them. The girl hastened to apologize. This is one of the psychosocial experiments demonstrating how beliefs and prejudices play a role.

5. The Bobo de Bbandura doll

Albert Bandura gained great fame for the Bobo doll experiment on child imitation aggression, where:

A group of children took as an example, by visual capacity, the adults in a room, without their behaviour being commented on, hit the Bobo doll. Other contemporaries, on the other hand, saw adults sitting, always in absolute silence, next to Bobo.

Finally, all these children were brought to a room full of toys, including a doll like Bobo. Of the 10 children who hit the doll, 8 were those who had seen it done before by an adult. This explains how if a model that we follow performs a certain action, we are tempted to imitate it and this happens especially in children who still do not have the experience to understand for themselves if that behaviour is correct or not.

6. Milgram’s experiment

The Milgram experiment was first carried out in 1961 by psychologist Stanley Milgram, as an investigation into the degree of our deference to authority. A subject is invited to give an electric shock to an individual playing the role of the student, positioned behind a screen when he does not answer a question correctly. An authorized person then tells the subject to gradually increase the intensity of the shock until the student screams in pain and begs to stop.

No justification is given, except for the fact that the authorized person tells the subject to obey. In reality, it was staged: there was absolutely no electric shock given, but in the experiment two-thirds of the subjects were influenced by what they thought was a 450-volt shock, simply because a person in authority told them they would not be responsible for it. nothing.

7. little Albert

We see little Albert’s experiment on unconditioned stimulus, which must be the most famous psychological study. John Watson and Rosalie Raynor showed a white laboratory rat to a nine-month-old boy, little Albert. At first, the boy showed no fear, but then Watson jumped up from behind and made him flinch with a sudden noise by hitting a metal bar with a hammer. Of course, the noise frightened little Albert, who began to cry.

Every time the rat was brought out, Watson and Raynor would rattle the bar with their hammer to scare the poor boy away. Soon the mere sight of the rat was enough to reduce little Albert to a trembling bundle of nerves: he had learned to fear the sight of a rat, and soon afterwards began to fear a series of similar objects shown to him.

8. Pavlov’s dog

Ivan Pavlov’s sheepdog became famous for his experiments that led him to discover what we call “classical conditioning” or “Pavlovian reflex” and is still a very famous psychological experiment today. Hardly any other psychological experiment is cited so often and with such gusto as Pavlov’s theory expounded in 1905: the Russian physiologist had been impressed by the fact that his dogs did not begin to drool at the sight of food, but rather when they heard it. to the laboratory employees who took it away.

He researched it and ordered a buzzer to ring every time it was mealtime. Very soon the sound of the doorbell was enough for the dogs to start drooling: they had connected the signal to the arrival of food.

9. Asch’s experiment

It is about a social psychology experiment carried out in 1951 by the Polish psychologist Solomon Asch on the influence of the majority and social conformity.

The experiment is based on the idea that being part of a group is a sufficient condition to change a person’s actions, judgments, and visual perceptions. The very simple experiment consisted of asking the subjects involved to associate line 1 drawn on a white sheet with the corresponding one, choosing between three different lines A, B, and C present on another sheet. Only one was identical to the other, while the other two were longer or shorter.

The experimentation was carried out in three phases. As soon as one of the subjects, Asch’s accomplice gave a wrong answer associating line 1 with the wrong one, the other members of the group also made the same mistake, even though the correct answer was more than obvious. The participants questioned the reason for this choice and responded that aware of the correct answer, they had decided to conform to the group, adapting to those who had preceded them.

psychotherapy definition types and techniques | Psychotherapy vs therapy Psychologyorg.com

10. Rosenbaum’s experiment

Among the most interesting investigations in this field, an experiment carried out by David Rosenhan (1923) to document the low validity of psychiatric diagnoses stands out. Rosenhan admitted eight assistants to various psychiatric hospitals claiming psychotic symptoms, but once they entered the hospital they behaved as usual.

Despite this, they were held on average for 19 days, with all but one being diagnosed as “psychotic”. One of the reasons why the staff is not aware of the “normality” of the subjects, is, according to Rosenhan, the very little contact between the staff and the patients.

11. Bystander Effect (1968)

The Bystander Effect studied in 1968 after the tragic case of Kitty Genovese, explores how individuals are less likely to intervene in emergencies when others are present. The original research by John Darley and Bibb Latané involved staged scenarios where participants believed they were part of a discussion via intercom.

In the experiment, participants were led to believe they were communicating with others about personal problems. Unknown to them, the discussions were staged, and at a certain point, a participant (confederate) pretended to have a seizure or needed help.

The results were startling. When participants believed they were the sole witness to the emergency, they responded quickly and sought help. However, when they thought others were also present (but were confederates instructed to not intervene), the likelihood of any individual offering help significantly decreased. This phenomenon became known as the Bystander Effect.

The diffusion of responsibility, where individuals assume others will take action, contributes to this effect. The presence of others creates a diffusion of responsibility among bystanders, leading to a decreased likelihood of any single individual taking action.

This experiment highlighted the social and psychological factors influencing intervention during emergencies and emphasized the importance of understanding bystander behaviour in critical situations.

The journey through the “11 Most Influential Psychological Experiments in History” illuminates the profound impact these studies have had on our understanding of human behaviour, cognition, and social dynamics.

Each experiment stands as a testament to the dedication of pioneering psychologists who dared to delve into the complexities of the human mind. From Milgram’s obedience studies to Zimbardo’s Stanford Prison Experiment, these trials have shaped not only the field of psychology but also our societal perceptions and ethical considerations in research.

They serve as timeless benchmarks, reminding us of the ethical responsibilities and the far-reaching implications of delving into the human psyche. The enduring legacy of these experiments lies not only in their scientific contributions but also in the ethical reflections they provoke, urging us to navigate the boundaries of knowledge with caution, empathy, and an unwavering commitment to understanding the intricacies of our humanity.

What is the most famous experiment in the history of psychology?

One of the most famous experiments is the Milgram Experiment, conducted by Stanley Milgram in the 1960s. It investigated obedience to authority figures and remains influential in understanding human behaviour.

Who wrote the 25 most influential psychological experiments in history?

The book “The 25 Most Influential Psychological Experiments in History” was written by Michael Shermer, a science writer and historian of science.

What is the history of experimental psychology?

Experimental psychology traces back to Wilhelm Wundt, often considered the father of experimental psychology. He established the first psychology laboratory in 1879 at the University of Leipzig, marking the formal beginning of experimental psychology as a distinct field.

What was the psychological experiment in the 1960s?

Many significant psychological experiments were conducted in the 1960s. One notable example is the Stanford Prison Experiment led by Philip Zimbardo, which examined the effects of situational roles on behaviour.

Who was the first experimental psychologist?

Wilhelm Wundt is often regarded as the first experimental psychologist due to his establishment of the first psychology laboratory and his emphasis on empirical research methods in psychology.

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I'm Waqar, a passionate psychologist and dedicated content writer. With a deep interest in understanding human behavior, I aim to share insights and knowledge in the field of psychology through this blog. Feel free to reach out for collaborations, queries, or discussions. Let's dig into the fascinating world of psychology together!

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20 Famous Psychology Experiments That Shaped Our Understanding

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Top 15 Interesting Facts about The Renaissance

1.stanford prison experiment.

2.Milgram Experiment

3.little albert experiment.

4.Asch Conformity Experiment

5.harlow’s monkey experiment.

6.Bobo Doll Experiment

7.the marshmallow test.

8.Robbers Cave Experiment

9.the monster study.

10.The Standford Marshmallow Experiment

11.the hawthorne effect.

12.The Strange Situation

13.the still face experiment.

14.Pavlov’s Dogs

15.the milgram experiment.

16.The Robbers Cave Experiment

17.the harlow monkey experiment, 18.the bystander effect, 19.the zimbardo prison experiment.

20.The Ainsworth Strange Situation Experiment

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Cognitive Psychology Experiments: Unveiling the Mysteries of the Mind

From illusions that deceive our senses to the limits of our memory, cognitive psychology experiments have long sought to unravel the enigmatic workings of the human mind. Our brains, these marvelous biological computers, continue to baffle and amaze us with their complexity and capabilities. Yet, through the tireless efforts of researchers and the ingenious design of experiments, we’ve managed to peek behind the curtain of consciousness and glimpse the inner workings of our cognitive processes.

Cognitive psychology, the study of mental processes such as attention, language use, memory, perception, problem-solving, creativity, and thinking, has been at the forefront of this exploration. It’s a field that bridges the gap between our subjective experiences and the objective world of scientific inquiry. By designing clever experiments, cognitive psychologists have managed to shine a light on the hidden mechanisms that drive our thoughts, decisions, and behaviors.

The journey of cognitive psychology began in the mid-20th century, emerging as a response to the limitations of behaviorism. While behaviorists focused solely on observable behaviors, cognitive psychologists argued that to truly understand the human mind, we needed to examine the internal mental processes that give rise to those behaviors. This shift in perspective opened up a whole new world of research possibilities, leading to a boom in experimental studies that continue to shape our understanding of the mind to this day.

The significance of these experiments cannot be overstated. They’ve not only advanced our theoretical understanding of cognition but have also had profound practical implications. From improving educational methods to developing more effective therapies for mental health disorders, the insights gained from cognitive psychology experiments have touched nearly every aspect of our lives.

Foundational Cognitive Psychology Experiments: The Building Blocks of Understanding

Let’s kick things off with a colorful conundrum that’s been puzzling psychologists for decades: the Stroop Effect. Imagine you’re presented with a list of color words, but here’s the catch – the words are printed in different colors than what they spell. For instance, the word “RED” might be printed in blue ink. Your task? Simply name the color of the ink, not read the word. Sounds easy, right? Well, prepare to have your mind blown!

Most people find this task surprisingly difficult, often stumbling and slowing down when the word and ink color don’t match. This phenomenon, first described by John Ridley Stroop in 1935, reveals the powerful interference between our automatic reading processes and our ability to name colors. It’s a prime example of how our cognitive processes can sometimes trip us up, even in seemingly simple tasks.

But wait, there’s more! Let’s take a stroll down memory lane with George Miller’s “Magic Number” experiment. In 1956, Miller proposed that our short-term memory capacity is limited to about seven items, plus or minus two. He arrived at this conclusion after presenting participants with lists of random items (like digits, letters, or words) and asking them to recall as many as possible.

Surprisingly, most people could remember about seven items, regardless of whether they were simple digits or complex concepts. This “magic number” has had far-reaching implications, influencing everything from the design of phone numbers to the way we organize information in user interfaces. It’s a testament to how a single, well-designed experiment can reshape our understanding of human cognition and impact our daily lives.

Now, let’s dive into the murky waters of memory reconstruction with Elizabeth Loftus and John Palmer’s groundbreaking work on eyewitness testimony. In their famous 1974 experiment, participants watched videos of car accidents and were then asked questions about what they saw. Here’s where it gets interesting: the researchers found that simply changing the wording of the questions could alter the participants’ memories of the event.

For instance, when asked “How fast were the cars going when they smashed into each other?”, participants estimated higher speeds than when the word “smashed” was replaced with “hit” or “contacted”. Even more astonishingly, a week later, participants who had been asked about the cars “smashing” were more likely to falsely remember seeing broken glass in the video – even though there was none!

This experiment sent shockwaves through the legal system, challenging the reliability of eyewitness testimony and highlighting the malleability of human memory. It’s a stark reminder that our memories aren’t perfect recordings of past events, but rather reconstructions that can be influenced by subsequent information and the way questions are phrased.

Attention and Perception Studies: The Invisible Gorilla and Other Mind-Bending Phenomena

Now, let’s turn our attention to… well, attention itself! One of the most jaw-dropping demonstrations of selective attention comes from Daniel Simons and Christopher Chabris’ “Gorilla in our midst” experiment. Picture this: you’re watching a video of people passing a basketball, and your task is to count the number of passes made by one team. Sounds simple enough, right? But here’s the kicker – in the middle of the video, a person in a gorilla suit walks right through the scene, beats their chest, and exits.

You’d think everyone would notice a gorilla, wouldn’t you? Surprisingly, about half of the participants in this experiment were so focused on counting passes that they completely missed the gorilla! This phenomenon, known as inattentional blindness, shows just how selective our attention can be. It’s a humbling reminder that we often see what we’re looking for and miss what we’re not expecting, even when it’s right in front of our eyes.

Speaking of missing things right in front of our eyes, let’s talk about change blindness. This phenomenon occurs when we fail to notice changes in our visual environment, even when they’re quite significant. In one famous demonstration, researchers showed participants alternating images of two people having a conversation. The images were identical except for one major change – in one image, the first person wore a hat, and in the other, they didn’t.

Astonishingly, many participants failed to notice this change, even after multiple viewings. This experiment highlights the limitations of our visual awareness and challenges our intuitive belief that we see and remember everything in our environment. It’s a sobering thought that we might be missing more of the world around us than we realize!

Lastly, let’s explore the world of visual search with Anne Treisman’s Feature Integration Theory experiments. Treisman proposed that our visual perception occurs in two stages: a pre-attentive stage where we process basic features like color and shape in parallel, and a focused attention stage where we combine these features into coherent objects.

To test this theory, Treisman conducted experiments where participants had to find a target item among distractors. She found that when the target differed from distractors in a single feature (like a red circle among blue circles), people could find it quickly regardless of the number of distractors. However, when the target was defined by a combination of features (like a red circle among blue circles and red squares), search times increased with the number of distractors.

These findings have had profound implications for our understanding of visual perception and attention. They’ve influenced everything from the design of user interfaces to strategies for improving visual search in real-world scenarios like airport security screenings.

Memory and Learning Experiments: Forgetting Curves and Spaced Repetition

Let’s take a journey back to the late 19th century, where Hermann Ebbinghaus was busy memorizing nonsense syllables. Why, you ask? Well, Ebbinghaus was on a mission to understand how our memory works, particularly how we forget information over time. His painstaking self-experiments led to the discovery of the “forgetting curve” – a graph showing how information is lost over time when there’s no attempt to actively recall it.

Ebbinghaus found that memory loss is rapid at first, but then levels off. For instance, he might forget 50% of the nonsense syllables within an hour, but then only forget another 10% over the next month. This insight has had profound implications for learning and education. It’s why cramming the night before an exam isn’t as effective as spaced repetition – reviewing material at gradually increasing intervals.

Speaking of context, let’s dive into the fascinating world of the Encoding Specificity Principle, brought to us by Endel Tulving and Donald Thomson. Their experiments showed that the context in which we learn information plays a crucial role in our ability to recall it later. In one study, participants learned lists of words either on dry land or underwater. Surprisingly, they were better at recalling the words in the same environment where they learned them.

This principle extends beyond physical environments to emotional states and even physiological conditions. Ever had trouble remembering something you knew you knew, only to have it pop into your head later in a different context? That’s the Encoding Specificity Principle at work! It’s a reminder that memory isn’t just about storing information, but about creating rich, contextual associations that aid in retrieval.

Now, let’s talk about a learning phenomenon that’s music to the ears of procrastinators everywhere – the Spacing Effect. This effect, first discovered by Hermann Ebbinghaus (yes, him again!) and later elaborated by many others, shows that we learn more effectively when we space out our study sessions over time, rather than cramming everything into one marathon session.

In a typical experiment demonstrating this effect, participants might be asked to learn a list of words. One group studies the list in a single session, while another group studies it in multiple shorter sessions spread out over time. When tested later, the spaced-learning group almost always outperforms the cramming group, even when the total study time is the same.

This finding has revolutionary implications for education and learning. It suggests that shorter, more frequent study sessions are more effective than longer, less frequent ones. So, the next time you’re tempted to pull an all-nighter before a big exam, remember – your brain might thank you for spreading out your study sessions instead!

Decision-Making and Problem-Solving Studies: Logic, Framing, and Functional Fixedness

Let’s kick off this section with a brain-teaser that’s stumped countless participants – the Wason Selection Task. Imagine you’re shown four cards. You know that each card has a letter on one side and a number on the other. The visible faces of the cards show A, D, 4, and 7. Now, you’re told there’s a rule: “If a card has a vowel on one side, then it has an even number on the other side.” Your task? Select only the cards you need to turn over to check if the rule is being followed.

Sounds simple, right? Well, prepare to have your mind boggled! Most people choose A and 4, but the correct answer is A and 7. This task, developed by Peter Wason in 1966, reveals our struggles with abstract logical reasoning. It’s a stark reminder that our brains aren’t naturally wired for formal logic, and that we often rely on intuitive shortcuts that can lead us astray.

Now, let’s shift gears to a phenomenon that’s shaped our understanding of decision-making – the Framing Effect. This cognitive bias, explored in depth by Amos Tversky and Daniel Kahneman, shows how the way information is presented (or “framed”) can dramatically influence our choices.

In one classic experiment, participants were presented with a hypothetical scenario where 600 people were at risk from a disease outbreak. They were then given two treatment options:

– Option A: “200 people will be saved” – Option B: “There’s a 1/3 probability that 600 people will be saved, and a 2/3 probability that no one will be saved”

Interestingly, most people chose Option A. But when the same scenario was presented with different framing:

– Option C: “400 people will die” – Option D: “There’s a 1/3 probability that nobody will die, and a 2/3 probability that 600 people will die”

Suddenly, most people preferred Option D, even though it’s mathematically equivalent to Option B!

This experiment reveals how our decisions can be swayed by the way information is presented, even when the underlying facts remain the same. It’s a sobering reminder of how susceptible we are to manipulation through framing, with implications ranging from marketing strategies to public health communications.

Lastly, let’s shine a light on a cognitive quirk that can hinder our problem-solving abilities – functional fixedness. This phenomenon was beautifully illustrated by Karl Duncker’s Candle Problem. In this experiment, participants were given a candle, a box of thumbtacks, and a book of matches. Their task? Attach the candle to the wall so that it can burn properly without dripping wax on the table below.

Many participants struggled with this task, trying to tack the candle directly to the wall or melt some of the wax to stick it. The solution, however, was to empty the box of thumbtacks, tack the box to the wall, and use it as a platform for the candle. The difficulty arose because people were fixated on the box’s function as a container for thumbtacks, failing to see its potential as a candleholder.

This experiment reveals how our preconceived notions about an object’s function can limit our problem-solving abilities. It’s a reminder to think outside the box – sometimes quite literally! – when faced with challenging problems.

Modern Cognitive Psychology Experiments: Peering into the Brain and Beyond

As we venture into the 21st century, cognitive psychology has embraced new technologies and methodologies, opening up exciting new avenues for research. One of the most revolutionary developments has been the advent of neuroimaging studies, which allow us to peek inside the brain as it performs various cognitive tasks.

Functional Magnetic Resonance Imaging (fMRI) studies, for instance, have allowed researchers to observe which areas of the brain “light up” during different cognitive processes. In one fascinating experiment, participants were asked to imagine walking through their homes while their brains were being scanned. The researchers found that different areas of the brain activated in sequence, corresponding to the mental “walk” through different rooms. This kind of study provides unprecedented insights into how our brains represent and navigate spatial information.

But it’s not just about pretty brain pictures. These neuroimaging studies have practical applications too. For example, they’ve been used to study the neural basis of cognitive biases, helping us understand why we’re prone to certain systematic errors in thinking. One study used fMRI to examine the brain activity of participants as they made financial decisions. The researchers found that when people experienced the “sunk cost fallacy” – continuing to invest in a failing project because of past investments – there was increased activity in areas of the brain associated with negative emotions and conflict resolution.

Speaking of cognitive biases, modern cognitive psychology has continued to uncover and explore these fascinating quirks of human thinking. One particularly intriguing area of research has been the study of the “Dunning-Kruger effect” – the tendency for people with low ability in a specific domain to overestimate their competence.

In a series of experiments, Justin Kruger and David Dunning asked participants to rate their abilities in various domains (like logical reasoning or grammar) and then tested their actual performance. They found that those who performed poorly on the tests consistently overestimated their abilities, while high performers tended to underestimate theirs. This effect has profound implications for everything from education to workplace dynamics, highlighting the importance of self-awareness and continuous learning.

Lastly, let’s talk about a hot topic in modern cognitive psychology – multitasking. In our hyper-connected world, many of us pride ourselves on our ability to juggle multiple tasks simultaneously. But what does the research say about the effects of multitasking on our attention and performance?

One eye-opening study by Eyal Ophir, Clifford Nass, and Anthony Wagner compared the cognitive abilities of heavy media multitaskers (people who frequently use multiple media simultaneously) with those of light media multitaskers. Contrary to what many might expect, they found that heavy multitaskers performed worse on tasks that required switching between different types of information. They were more easily distracted by irrelevant information and had more difficulty organizing their memories.

This research challenges the common belief that multitasking makes us more efficient. Instead, it suggests that constantly dividing our attention might be impairing our ability to focus and process information effectively. It’s a sobering thought in an age where we’re constantly bombarded with information from multiple sources.

As we wrap up our whirlwind tour of cognitive psychology experiments, it’s clear that this field has come a long way since its inception. From the foundational studies that shaped our understanding of attention, memory, and perception, to the cutting-edge research using neuroimaging and exploring cognitive biases, each experiment has added a piece to the puzzle of the human mind.

These studies have not only advanced our theoretical understanding but have also had profound practical implications. They’ve influenced educational practices, shaped legal procedures, informed design principles, and even changed how we think about our own thinking. The insights gained from cognitive psychology experiments have truly permeated every aspect of our lives.

As we look to the future, the field of cognitive psychology continues to evolve. Emerging technologies like virtual reality and artificial intelligence are opening up new possibilities for experimental design and data analysis. At the same time, there’s a growing recognition of the need for more diverse and representative participant pools to ensure that our understanding of cognition isn’t limited to a narrow subset of humanity.

One thing is certain – the human mind remains as fascinating and mysterious as ever. As we continue to probe its depths through clever experiments and rigorous analysis, we’re sure to uncover even more surprises. Who knows? The next groundbreaking cognitive psychology experiment might be just around the corner, ready to revolutionize our understanding of the mind once again.

So, the next time you find yourself marveling at the quirks of your own thinking – whether you’re struggling to ignore the word “RED” written in blue ink, or wondering how you missed that gorilla in the basketball game – remember that you’re experiencing firsthand the phenomena that cognitive psychologists have been studying for decades. Our minds may be enigmatic, but with each experiment, we get a little closer to unraveling their mysteries.

References:

1. Stroop, J. R. (1935). Studies of interference in serial verbal reactions. Journal of Experimental Psychology, 18(6), 643-662.

2. Miller, G. A. (1956). The magical number seven, plus or minus two: Some limits on our capacity for processing information. Psychological Review, 63(2), 81-97.

3. Loftus, E. F., & Palmer, J. C. (1974). Reconstruction of automobile destruction: An example of the interaction between language and memory. Journal of Verbal Learning and Verbal Behavior, 13(5), 585-589.

4. Simons, D. J., & Chabris, C. F. (1999). Gorillas in our midst: Sustained inattentional blindness for dynamic events. Perception, 28(9), 1059-1074.

5. Treisman, A. M., & Gelade, G. (1980). A feature-integration theory of attention. Cognitive Psychology, 12(1), 97-136.

6. Ebbinghaus, H. (1885/1913). Memory: A contribution to experimental psychology. New York: Teachers College, Columbia University.

7. Tulving, E., & Thomson, D. M. (1973). Encoding specificity and retrieval processes in episodic memory. Psychological Review, 80(5), 352-373.

8. Wason, P. C. (1966). Reasoning. In B. M. Foss (Ed.), New horizons in psychology. Harmondsworth: Penguin.

9. Tversky, A., & Kahneman, D. (1981). The framing of decisions and the psychology of choice. Science, 211(4481), 453-458.

10. Duncker, K. (1945). On problem-solving. Psychological Monographs, 58(5), i-113.

11. Kruger, J., & Dunning, D. (1999). Unskilled and unaware of it: How difficulties in recognizing one’s own incompetence lead to inflated self-assessments. Journal of Personality and Social Psychology, 77(6), 1121-1134.

12. Ophir, E., Nass, C., & Wagner, A. D. (2009). Cognitive control in media multitaskers. Proceedings of the National Academy of Sciences, 106(37), 15583-15587.

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8 Classic Psychological Experiments

Categories History

Psychological experiments can tell us a lot about the human mind and behavior. Some of the best-known experiments have given us insights into topics such as conformity, obedience, attachment, and learning.

There are many famous (and sometimes infamous) psychological experiments that have helped shape our understanding of the human mind and behavior. Such experiments offered insights into how people respond to social pressure and how they develop associations that lead to fear. 

While many of these psychological experiments are well known even outside of psychology, it is important to recognize that many of them could not be performed today.

In many instances, these experiments would never receive institutional review board approval due to ethical concerns and the potential harm to participants.

In this article, learn more about some of the most famous psychological experiments and discover why some of them are considered so controversial.

Table of Contents

Pavlov’s Dog Experiments, 1897

While not set up as a psychological experiment, Ivan Pavlov’s research on the digestive systems of dogs had a tremendous impact on the field of psychology. During his research, he noticed that dogs would begin to salivate whenever they saw the lab assistant who provided them with food.

By pairing a previously neutral stimulus (a sound) with a naturally occurring stimulus that automatically produces a response (food), Pavlov discovered that he could condition the dogs to salivate when they heard the sound.

The discovery of the classical conditioning process played a pivotal role in the formation of the behavioral school of psychology and has continued to influence our understanding of how learning can occur through associations.

Little Albert Experiment, 1920

Anyone who has ever taken an introductory course in psychology is probably familiar with the Little Albert experiment. In the famous experiment conducted in the 1920s by behaviorists John B. Watson and Rosalie Rayner, an infant was exposed to a white rat to which he initially exhibited no fear. The researchers then presented the rat accompanied by a loud clanging noise. 

After repeated pairings, the child began to cry when the rat alone was presented. This fear was even generalized to objects that resembled the rat such as fluffy white toys.

Watson’s research played an important role in the development of the school of thought known as behaviorism . It also provided evidence of the power of classical conditioning , which involves learning by association. 

The findings also had implications for our understanding of how fears can form, including phobias and irrational fears that sometimes develop early in life or after a single frightening experience.

Asch Conformity Experiment, 1951

The Asch conformity experiments were a series of psychological experiments conducted by psychologist Solomon Asch during the 1950s. The purpose of the experiments was to determine how much a person’s opinions were influenced by the opinions of the rest of the group.

In the study, participants were told that they were taking a “vision test” along with several others. In reality, the other individuals in the room were actors who were following the experimenters’ instructions.

When shown several line segments, the participants were supposed to select the one that matched a sample line segment in length.

In some cases, those who were in on the study would pick the obvious match. In other cases, however, the study confederates would unanimously pick the wrong line segment. 

The results of Asch’s experiments found that people tended to conform when other people unanimously picked the wrong answer.

Across the 12 trials he conducted, Asch found that around 33% of the naive participants conformed to the group and picked the wrong answer. In a control group, for comparison, less than 1% of the participants ever chose the wrong answer. 

The experiments revealed how group pressure can cause people to change their own behavior in order to fit in with the rest of the group.

Robbers Cave Experiment, 1954

In the Robbers Cave psychological experiment , researcher Muzafer Sherif and his colleagues used a summer camp setting to look at how factors such as competition and prejudice influenced conflict between groups. 

In the experiment, boys attending a summer camp were randomly assigned to two groups. The groups were then placed in situations where they had to compete with one another. Such competition led to conflicts, competition, and hostility between the two groups.

Later, the experiments attempted to reconcile the groups and eliminate the tensions that the previous competitive tasks had created. Bonding activities had little impact, but the researchers found that situations that required members of the two groups to work together in order to overcome a problem were effective at reducing tensions.

The study had implications for how different social groups create their own norms and hierarchies and then use those rules to exclude outsiders.

Harlow’s Rhesus Monkey Experiments, 1958

Psychologist Harry Harlow conducted a series of experiments during the 1950s and 1960s that demonstrated how important love and affection were in the course of child development. In his experiments, he placed infant monkeys in an environment where they had access to two different surrogate “mothers.”

One was a wire mother who held a bottle and provided food, while the other was a soft surrogate mother who was covered in a terry cloth fabric. 

While the cloth mother did not provide nourishment, the experiments demonstrated that the baby monkeys preferred the soft mother over the wire mother. When they were frightened and needed comfort, they would turn to the cloth mother for security.

Milgram Obedience Experiment, 1963

The Milgram experiment was one of the most famous and controversial psychological experiments ever performed. The experiments involved an experimenter ordering participants to deliver electrical shocks to other people.

While the people who were supposedly receiving the shocks were actors who pretended to be in pain, the participants fully believed that they were delivering painful, and even dangerous shocks. 

Milgram’s findings suggested that up to 65% of the participants were willing to deliver potentially fatal shocks to another person simply because an authority figure ordered them to do so. 

Based on these findings, Milgram proposed that people were willing to follow orders from an authority figure if they think that person will take responsibility for the results and is qualified to give orders. 

Bobo Doll Experiment, 1961-1963

In this experiment, Albert Bandura investigated the effects of observational learning by having young children witness acts of aggression and then observing them to see if they copied the behavior.

Children in the study observed adults act aggressively toward a Bobo doll, a large inflatable doll resembling a bowling pin. When hit or kicked, the doll tips sideways and then returns to an upright position.

Bandura found that children who watched an adult act aggressively were more likely to imitate those behaviors later when they were allowed to play in a room with the Bobo doll.

The study played an important role in our understanding of social learning theory and how kids learn by watching others. 

Stanford Prison Experiment, 1971

In this infamous social psychology experiment, Philip Zimbardo set up a mock prison in the basement of the Stanford University psychology department and randomly assigned a group of 24 college students to either be guards or prisoners. 

The study was originally supposed to last for two weeks but had to be stopped after six days because participants reportedly became so immersed in their roles that they began to experience upsetting psychological effects. The results were believed to demonstrate the power that social roles and expectations can exert over a person’s behavior. 

The experiment is widely described in psychology textbooks and even became the subject of a feature film in 2015. 

More recent analysis has suggested that the experiment had serious design flaws, among other problems. In addition to the already problematic ethics of the study, analysis of the study’s records suggests that the experimenters may have played a role in encouraging the abusive behavior displayed by the participants.

Impact of Psychological Experiments

The psychology experiments of the past have had an impact on our understanding of the human mind and behavior. While many of the experiments described here have problems in terms of their design and their ethics, they remain some of the most famous examples of research within the field of psychology.

Learning more about these classic experiments can help you better understand research that informed the development of psychology. It can also provide inspiration for your own psychology experiment ideas and provide information to explore in your psychology papers .

Bandura A, Ross D, Ross SA. Transmission of aggression through imitation of aggressive models . Journal of Abnormal and Social Psychology. 1961;63:575-82. doi:10.1037/h0045925

Gantt WH . Ivan Pavlov . Encyclopaedia Brittanica . Updated February 23, 2020.

Gonzalez-franco M, Slater M, Birney ME, Swapp D, Haslam SA, Reicher SD. Participant concerns for the Learner in a Virtual Reality replication of the Milgram obedience study. PLoS ONE. 2018;13(12):e0209704. doi:10.1371/journal.pone.0209704

Jeon, HL. The environmental factor within the Solomon Asch Line Test . International Journal of Social Science and Humanity. 2014;4(4):264-268. doi:10.7763/IJSSH.2014.V4.360 

Le Texier T. Debunking the Stanford Prison Experiment . American Psychologist . 2019;74(7):823-839. doi:10.1037/amp0000401

Sherif M, Harvey OJ, White BJ, Hood WR, Sherif CW. Intergroup conflict and cooperation: The Robbers Cave experiment (Vol. 10) . Norman, OK: University Book Exchange; 1961.

Zimbardo P, Haney C, Banks WC, Jaffe D. The Stanford Prison Experiment: A simulation study of the psychology of imprisonment. Stanford University, Stanford Digital Repository, Stanford; 1971.

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7 Famous Psychology Experiments

Many famous experiments studying human behavior have impacted our fundamental understanding of psychology. Though some could not be repeated today due to breaches in ethical boundaries, that does not diminish the significance of those psychological studies. Some of these important findings include a greater awareness of depression and its symptoms, how people learn behaviors through the process of association and how individuals conform to a group.

Below, we take a look at seven famous psychological experiments that greatly influenced the field of psychology and our understanding of human behavior.

The Little Albert Experiment, 1920

A John’s Hopkins University professor, Dr. John B. Watson, and a graduate student wanted to test a learning process called classical conditioning. Classical conditioning involves learning involuntary or automatic behaviors by association, and Dr. Watson thought it formed the bedrock of human psychology.

A nine-month-old toddler, dubbed “Albert B,” was volunteered for Dr. Watson and Rosalie Rayner ‘s experiment. Albert played with white furry objects, and at first, the toddler displayed joy and affection. Over time, as he played with the objects, Dr. Watson would make a loud noise behind the child’s head to frighten him. After numerous trials, Albert was conditioned to be afraid when he saw white furry objects.

The study proved that humans could be conditioned to enjoy or fear something, which many psychologists believe could explain why people have irrational fears and how they may have developed early in life. This is a great example of experimental study psychology.

Stanford Prison Experiment, 1971

Stanford professor Philip Zimbardo wanted to learn how individuals conformed to societal roles. He wondered, for example, whether the tense relationship between prison guards and inmates in jails had more to do with the personalities of each or the environment.

During Zimbardo’s experiment , 24 male college students were assigned to be either a prisoner or a guard. The prisoners were held in a makeshift prison inside the basement of Stanford’s psychology department. They went through a standard booking process designed to take away their individuality and make them feel anonymous. Guards were given eight-hour shifts and tasked to treat the prisoners just like they would in real life.

Zimbardo found rather quickly that both the guards and prisoners fully adapted to their roles; in fact, he had to shut down the experiment after six days because it became too dangerous. Zimbardo even admitted he began thinking of himself as a police superintendent rather than a psychologist. The study confirmed that people will conform to the social roles they’re expected to play, especially overly stereotyped ones such as prison guards.

“We realized how ordinary people could be readily transformed from the good Dr. Jekyll to the evil Mr. Hyde,” Zimbardo wrote.

The Asch Conformity Study, 1951

Solomon Asch, a Polish-American social psychologist, was determined to see whether an individual would conform to a group’s decision, even if the individual knew it was incorrect. Conformity is defined by the American Psychological Association as the adjustment of a person’s opinions or thoughts so that they fall closer in line with those of other people or the normative standards of a social group or situation.

In his experiment , Asch selected 50 male college students to participate in a “vision test.” Individuals would have to determine which line on a card was longer. However, the individuals at the center of the experiment did not know that the other people taking the test were actors following scripts, and at times selected the wrong answer on purpose. Asch found that, on average over 12 trials, nearly one-third of the naive participants conformed with the incorrect majority, and only 25 percent never conformed to the incorrect majority. In the control group that featured only the participants and no actors, less than one percent of participants ever chose the wrong answer.

Asch’s experiment showed that people will conform to groups to fit in (normative influence) because of the belief that the group was better informed than the individual. This explains why some people change behaviors or beliefs when in a new group or social setting, even when it goes against past behaviors or beliefs.

The Bobo Doll Experiment, 1961, 1963

Stanford University professor Albert Bandura wanted to put the social learning theory into action. Social learning theory suggests that people can acquire new behaviors “through direct experience or by observing the behavior of others.” Using a Bobo doll , which is a blow-up toy in the shape of a life-size bowling pin, Bandura and his team tested whether children witnessing acts of aggression would copy them.

Bandura and two colleagues selected 36 boys and 36 girls between the ages of 3 and 6 from the Stanford University nursery and split them into three groups of 24. One group watched adults behaving aggressively toward the Bobo doll. In some cases, the adult subjects hit the doll with a hammer or threw it in the air. Another group was shown an adult playing with the Bobo doll in a non-aggressive manner, and the last group was not shown a model at all, just the Bobo doll.

After each session, children were taken to a room with toys and studied to see how their play patterns changed. In a room with aggressive toys (a mallet, dart guns, and a Bobo doll) and non-aggressive toys (a tea set, crayons, and plastic farm animals), Bandura and his colleagues observed that children who watched the aggressive adults were more likely to imitate the aggressive responses.

Unexpectedly, Bandura found that female children acted more physically aggressive after watching a male subject and more verbally aggressive after watching a female subject. The results of the study highlight how children learn behaviors from observing others.

The Learned Helplessness Experiment, 1965

Martin Seligman wanted to research a different angle related to Dr. Watson’s study of classical conditioning. In studying conditioning with dogs, Seligman made an astute observation : the subjects, which had already been conditioned to expect a light electric shock if they heard a bell, would sometimes give up after another negative outcome, rather than searching for the positive outcome.

Under normal circumstances, animals will always try to get away from negative outcomes. When Seligman tested his experiment on animals who hadn’t been previously conditioned, the animals attempted to find a positive outcome. Oppositely, the dogs who had been already conditioned to expect a negative response assumed there would be another negative response waiting for them, even in a different situation.

The conditioned dogs’ behavior became known as learned helplessness, the idea that some subjects won’t try to get out of a negative situation because past experiences have forced them to believe they are helpless. The study’s findings shed light on depression and its symptoms in humans.

Is a Psychology Degree Right for You?

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The Milgram Experiment, 1963

In the wake of the horrific atrocities carried out by Nazi Germany during World War II, Stanley Milgram wanted to test the levels of obedience to authority. The Yale University professor wanted to study if people would obey commands, even when it conflicted with the person’s conscience.

Participants of the condensed study , 40 males between the ages of 20 and 50, were split into learners and teachers. Though it seemed random, actors were always chosen as the learners, and unsuspecting participants were always the teachers. A learner was strapped to a chair with electrodes in one room while the experimenter äóñ another actor äóñ and a teacher went into another.

The teacher and learner went over a list of word pairs that the learner was told to memorize. When the learner incorrectly paired a set of words together, the teacher would shock the learner. The teacher believed the shocks ranged from mild all the way to life-threatening. In reality, the learner, who intentionally made mistakes, was not being shocked.

As the voltage of the shocks increased and the teachers became aware of the believed pain caused by them, some refused to continue the experiment. After prodding by the experimenter, 65 percent resumed. From the study, Milgram devised the agency theory , which suggests that people allow others to direct their actions because they believe the authority figure is qualified and will accept responsibility for the outcomes. Milgram’s findings help explain how people can make decisions against their own conscience, such as when participating in a war or genocide.

The Halo Effect Experiment, 1977

University of Michigan professors Richard Nisbett and Timothy Wilson were interested in following up a study from 50 years earlier on a concept known as the halo effect . In the 1920s, American psychologist Edward Thorndike researched a phenomenon in the U.S. military that showed cognitive bias. This is an error in how we think that affects how we perceive people and make judgements and decisions based on those perceptions.

In 1977, Nisbett and Wilson tested the halo effect using 118 college students (62 males, 56 females). Students were divided into two groups and were asked to evaluate a male Belgian teacher who spoke English with a heavy accent. Participants were shown one of two videotaped interviews with the teacher on a television monitor. The first interview showed the teacher interacting cordially with students, and the second interview showed the teacher behaving inhospitably. The subjects were then asked to rate the teacher’s physical appearance, mannerisms, and accent on an eight-point scale from appealing to irritating.

Nisbett and Wilson found that on physical appearance alone, 70 percent of the subjects rated the teacher as appealing when he was being respectful and irritating when he was cold. When the teacher was rude, 80 percent of the subjects rated his accent as irritating, as compared to nearly 50 percent when he was being kind.

The updated study on the halo effect shows that cognitive bias isn’t exclusive to a military environment. Cognitive bias can get in the way of making the correct decision, whether it’s during a job interview or deciding whether to buy a product that’s been endorsed by a celebrity we admire.

How Experiments Have Impacted Psychology Today

Contemporary psychologists have built on the findings of these studies to better understand human behaviors, mental illnesses, and the link between the mind and body. For their contributions to psychology, Watson, Bandura, Nisbett and Zimbardo were all awarded Gold Medals for Life Achievement from the American Psychological Foundation. Become part of the next generation of influential psychologists with King University’s online bachelor’s in psychology . Take advantage of King University’s flexible online schedule and complete the major coursework of your degree in as little as 16 months. Plus, as a psychology major, King University will prepare you for graduate school with original research on student projects as you pursue your goal of being a psychologist.

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Chinese scientists have put human brain genes in monkeys—and yes, they may be smarter

• Antonio Regalado archive page

Human intelligence is one of evolution’s most consequential inventions. It is the result of a sprint that started millions of years ago, leading to ever bigger brains and new abilities. Eventually, humans stood upright, took up the plow, and created civilization, while our primate cousins stayed in the trees.

Now scientists in southern China report that they’ve tried to narrow the evolutionary gap, creating several transgenic macaque monkeys with extra copies of a human gene suspected of playing a role in shaping human intelligence.

“This was the first attempt to understand the evolution of human cognition using a transgenic monkey model,” says Bing Su, the geneticist at the Kunming Institute of Zoology who led the effort.

According to their findings, the modified monkeys did better on a memory test involving colors and block pictures, and their brains also took longer to develop—as those of human children do. There wasn’t a difference in brain size.

The experiments, described on March 27 in a Beijing journal, National Science Review, and first reported by Chinese media, remain far from pinpointing the secrets of the human mind or leading to an uprising of brainy primates.

Instead, several Western scientists, including one who collaborated on the effort, called the experiments reckless and said they questioned the ethics of genetically modifying primates, an area where China has seized a technological edge.

“The use of transgenic monkeys to study human genes linked to brain evolution is a very risky road to take,” says James Sikela, a geneticist who carries out comparative studies among primates at the University of Colorado. He is concerned that the experiment shows disregard for the animals and will soon lead to more extreme modifications. “It is a classic slippery slope issue and one that we can expect to recur as this type of research is pursued,” he says.

Research using primates is increasingly difficult in Europe and the US, but China has rushed to apply the latest high-tech DNA tools to the animals. The country was first to create monkeys altered with the gene-editing tool CRISPR , and this January a Chinese institute announced it had produced a half-dozen clones of a monkey with a severe mental disturbance .

“It is troubling that the field is steamrolling along in this manner,” says Sikela. 

Evolution story

Su, a researcher at the Kunming Institute of Zoology, specializes in searching for signs of “Darwinian selection”—that is, genes that have been spreading because they’re successful. His quest has spanned such topics as Himalayan yaks’ adaptation to high altitude and the evolution of human skin color in response to cold winters.

The biggest riddle of all, though, is intelligence. What we know is that our humanlike ancestors’ brains rapidly grew in size and power. To find the genes that caused the change, scientists have sought out differences between humans and chimpanzees, whose genes are about 98% similar to ours. The objective, says, Sikela, was to locate “ the jewels of our genome ”—that is, the DNA that makes us uniquely human.

For instance, one popular candidate gene called FOXP2 —the “language gene” in press reports—became famous for its potential link to human speech. (A British family whose members inherited an abnormal version had trouble speaking.) Scientists from Tokyo to Berlin were soon mutating the gene in mice and listening with ultrasonic microphones to see if their squeaks changed.  

Su was fascinated by a different gene:  MCPH1 , or microcephalin. Not only did the gene’s sequence differ between humans and apes, but babies with damage to microcephalin are born with tiny heads, providing a link to brain size. With his students, Su once used calipers and head spanners to the measure the heads of 867 Chinese men and women to see if the results could be explained by differences in the gene.

By 2010, though, Su saw a chance to carry out a potentially more definitive experiment—adding the human microcephalin gene to a monkey. China by then had begun pairing its sizable breeding facilities for monkeys (the country exports more than 30,000 a year) with the newest genetic tools, an effort that has turned it into a mecca for foreign scientists who need monkeys to experiment on.

To create the animals, Su and collaborators at the Yunnan Key Laboratory of Primate Biomedical Research exposed monkey embryos to a virus carrying the human version of microcephalin. They generated 11 monkeys, five of which survived to take part in a battery of brain measurements. Those monkeys each have between two and nine copies of the human gene in their bodies.

Su’s monkeys raise some unusual questions about animal rights. In 2010, Sikela and three colleagues wrote a paper called “ The ethics of using transgenic non-human primates to study what makes us human ,” in which they concluded that human brain genes should never be added to apes, such as chimpanzees, because they are too similar to us.

“You just go to the Planet of the Apes immediately in the popular imagination,” says Jacqueline Glover, a University of Colorado bioethicist who was one of the authors. “To humanize them is to cause harm. Where would they live and what would they do? Do not create a being that can’t have a meaningful life in any context.”

The authors concluded, however, that it might be acceptable to make such changes to monkeys.

In an e-mail, Su says he agrees that apes are so close to humans that their brains shouldn’t be changed. But monkeys and humans last shared an ancestor 25 million years ago. To Su, that alleviates the ethical concerns. “Although their genome is close to ours, there are also tens of millions of differences,” he says. He doesn’t think the monkeys will become anything more than monkeys. “Impossible by introducing only a few human genes,” he says. 

Smart monkey?

Judging by their experiments, the Chinese team did expect that their transgenic monkeys could end up with increased intelligence and brain size. That is why they put the creatures inside MRI machines to measure their white matter and gave them computerized memory tests. According to their report, the transgenic monkeys didn’t have larger brains, but they did better on a short-term memory quiz, a finding the team considers remarkable.

Several scientists think the Chinese experiment didn’t yield much new information. One of them is Martin Styner, a University of North Carolina computer scientist and specialist in MRI who is listed among the coauthors of the Chinese report. Styner says his role was limited to training Chinese students to extract brain volume data from MRI images, and that he considered removing his name from the paper, which he says was not able to find a publisher in the West.

“There are a bunch of aspects of this study that you could not do in the US,” says Styner. “It raised issues about the type of research and whether the animals were properly cared for.”

After what he’s seen, Styner says he’s not looking forward to more evolution research on transgenic monkeys. “I don’t think that is a good direction,” he says. “Now we have created this animal which is different than it is supposed to be. When we do experiments, we have to have a good understanding of what we are trying to learn, to help society, and that is not the case here.” One issue is that genetically modified monkeys are expensive to create and care for. With just five modified monkeys, it’s hard to reach firm conclusions about whether they really differ from normal monkeys in terms of brain size or memory skills. “They are trying to understand brain development. And I don’t think they are getting there,” says Styner.

In an e-mail, Su agreed that the small number of animals was a limitation. He says he has a solution, though. He is making more of the monkeys and is also testing new brain evolution genes. One that he has his eye on is SRGAP2C , a DNA variant that arose about two million years ago, just when Australopithecus was ceding the African savannah to early humans. That gene has been dubbed the “ humanity switch ” and the “ missing genetic link ” for its likely role in the emergence of human intelligence.

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18 brain studies that blew our minds in 2023

From its strange "spiral signals" to a libido switch, the brain contains myriad mysteries that scientists are still working to unravel.

Perhaps the most mysterious organ in the body, the brain continues to astound scientists despite the countless hours they've spent attempting to decipher its inner workings. Each new discovery about the brain brings a thousand new questions in its wake.

Here are 18 things we learned about the brain in 2023 that blew our minds.

Related: Do we really use only 10% of our brains?

1. Newly discovered part of the brain

In January, scientists described their discovery of a kind of shield in the brain that helps clear away waste and acts as a look-out post for immune cells. The thin shield seems to help control the flow of proteins and molecules between different compartments containing cerebrospinal fluid, a colorless liquid that flows around the brain and within tubes through the organ.

2. Squid and human brains tied by evolution

Despite the 500 million years of evolution that separate squids and humans, our brains develop in a very similar way to the brains of these cephalopods. Scientists discovered this by monitoring stem cells called neural progenitor cells in developing squid embryos. To build a squid retina, where most of the animal's neural tissue is found, the cells must first form a long, densely packed structure that can also be spotted during the neural development of vertebrates like us.

3. 'Junk DNA' and big brains

The genes that enabled humans to grow notably big brains may have originally come from "junk DNA," which doesn't code for any proteins, researchers revealed early this year. At some point in human evolution, after we split from other primates, some of this junk DNA picked up the ability to encode proteins. In animal and lab-dish experiments, several of these genes appeared key for boosting brain growth.

4. Injuries plugged with minibrains

Scientists used cerebral organoids — miniature 3D models of the brain — to repair brain injuries in rats . The organoids were grown from human stem cells and transplanted into rats' visual cortices, the region of the brain where information from the eyes is initially processed. The researchers hope to eventually apply the technique in humans, but that's many years away.

5. Native language wires the brain

A person's native language may influence how their brain links up information-processing hubs within its structure, according to a study of people whose native languages were German and Arabic published in February. Differences in the study participants' brains were chalked up to linguistic differences between the languages. However, more work is needed to reveal how cultural features of conversation might shape brain structure.

6. Psychedelics invade brain cells

Psychedelics have shown promise as therapies for hard-to-treat depression, and now scientists think it may be because they invade brain cells . Psychedelics, such as LSD, DMT and psilocybin, can bind to receptors for the chemical messenger serotonin — but significantly, they can latch onto these receptors on the outside and inside of cells. Theoretically, this means psychedelics might flip switches that traditional antidepressants, which generally increase the concentration of serotonin outside the cells, can't reach. That may be why trippy drugs drive brain cells toward building new connections.

7. Never-before-seen brain wave

Octopuses generate a type of brain wave not seen in any other animal, even humans. These long-lasting, unusually slow brain waves were recorded using electrodes implanted in freely moving octopuses' brains. Scientists aren't yet sure what function these unique waves serve, or if they're tied to a specific behavior.

8. Short-circuiting chronic pain

The brains of people with chronic pain show fluctuating patterns of activity that can be tied to the subjective experience of their pain, researchers have discovered. Deciphering these patterns could someday enable doctors to disrupt them with targeted therapies, thus short-circuiting patients' pain.

9. Brain surgery in the womb

In a first-of-its-kind surgery, doctors repaired a malformed blood vessel in a fetus' brain prior to birth. The malformation occurs in an estimated 1 in 60,000 births and is usually treated after birth, when it can sometimes be too late to prevent damage or death. In March, doctors successfully treated the malformation sooner, in the womb.

10. Life flashing before your eyes?

People's brains generate a flurry of activity in their last minutes of life, scientists revealed in May, and this electrical surge may reflect conscious experiences — however, that's just a theory. It could be that this activity erupts as people "move toward the light" or see their "lives flashing before their eyes," as portrayed in many movies. Or, it could also just be "aberrant electrophysiological activity," some experts say.

11. Mystery brain spiral signals

Spiral signals uncovered in the human brain may help organize the organ's complex activity. The spirals are brain waves that pass over the surface of the brain and rotate around central points. These spirals may act as bridges of communication between different regions of the brain, scientists theorized in June.

12. Sex switch in mouse brains

Scientists discovered an "on switch" for libido in the male mouse brain — and they think a similar control center may exist in humans, although they haven't found such circuitry yet. Flipping the switch drove male mice to mate with females and with inanimate objects, and also reduced the break time needed between rounds of sex. As of now, no equivalent circuit has been found in female mice.

13. Pink Floyd in brain waves

In August, scientists revealed they were able to "read" people's brain waves and recreate Pink Floyd's famous "Another Brick in the Wall," which the volunteers had listened to during their brain recordings. Some song snippets generated by the researchers really did sound like the 1979 protest song — other snippets, however, sounded much muddier.

14. A 'tell' for false memories

Your brain's activity shifts in a distinct way when you're about to recall a false memory , or one in which the events never really happened. This "tell" specifically crops up in the hippocampus, a key brain region for memory, scientists recently discovered.

15. Brain changes across menstrual cycle 

The brain's structure goes through subtle changes throughout a person's menstrual cycle . These changes appear in the microstructure of the brain's white matter — the insulated wires that run between brain cells — as well as the thickness of its gray matter, the bodies of brain cells. For now, it's unknown whether these brain changes affect cognition or the risk of brain diseases. But the research could open the door to such discoveries in the future.

16. Complete insect brain map

The first-ever complete map of an insect's brain contains 3,016 neurons. The fruit fly brain atlas, completed over 12 years and finally revealed in June, shows all the physical connections between the thousands of cells. It could help pave the way for more-advanced artificial intelligence (AI) systems and help scientists decipher similar structures in the human brain.

17. Most-complete human brain map ever

This year, scientists unveiled the most detailed atlas of the human brain ever conceived which details the arrangement of 3,300 types of brain cells, few of which were previously known to science. The atlas is half composed of neurons — the brain cells that communicate through chemical and electrical messages — and half made up of non-neuronal cells.

18. Minibrain plugged into AI

— How many calories can the brain burn by thinking?

— Consciousness can't be explained by brain chemistry alone, one philosopher argues

— Can minds persist when they are cut off from the world?

For the first time, scientists plugged a brain organoid into the middle of an AI system and used the hybrid computer to perform tasks and computations. The experiment could help pave the way for biocomputers that borrow tricks from biology to become more energy efficient than standard computers.

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Nicoletta Lanese is the health channel editor at Live Science and was previously a news editor and staff writer at the site. She holds a graduate certificate in science communication from UC Santa Cruz and degrees in neuroscience and dance from the University of Florida. Her work has appeared in The Scientist, Science News, the Mercury News, Mongabay and Stanford Medicine Magazine, among other outlets. Based in NYC, she also remains heavily involved in dance and performs in local choreographers' work.

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How pieces of live human brain are helping scientists map nerve cells.

An audacious project aims to figure out how humans are different from other creatures

MENAGERIE OF NEURONS  Studies of live human brain tissue have revealed cells like this reconstructed pyramidal nerve cell in exquisite detail.

Allen Institute

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By Laura Sanders

August 7, 2019 at 6:00 am

The golf ball–sized chunk of brain is not cooperating. It’s thicker than usual, and bloodier. One side has a swath of tissue that looks, to my untrained eye, like gristle.

Nick Dee, the neuroscientist charged with quickly cutting the chunk into neat pieces, confers with his colleagues. “We can trim off that ugliness on the side,” he says. The “ugliness” is the brain’s connective tissue called white matter.

To produce useful slices for experiments, the brain tissue must be trimmed, superglued to a lipstick-sized base and then fed into a lab version of a deli slicer. But this difficult chunk isn’t cutting nicely. Dee and colleagues pull it off the base, trim it again and reglue.

Half an hour earlier, this piece of neural tissue was tucked inside a 41-year-old woman’s head, on her left side, just above the ear. Surgeons removed the tissue to reach a deeper part of her brain thought to be causing severe seizures. Privacy rules prevent me from knowing much about her; I don’t know her name, much less her first memory, favorite meal or sense of humor. But within this piece of tissue, which the patient generously donated, are clues to how her brain — all of our brains, really — create the mind.

Dee’s team is working fast because this piece of brain is alive. Some of the cells can still behave as if they are a part of a person’s brain, which means they hold enormous potential for scientists who want to understand how we remember, plan, behave and feel. After Dee and his team do their part, pieces of the woman’s brain will be whisked into the hands of eager scientists, where the cells will be photographed, zapped with electricity, relieved of their genetic material and even infected with viruses that make them glow green and red.

It’s all part of a project at the Seattle-based Allen Institute for Brain Science, funded largely by private money plus some U.S. government grants. Now in its sixth year, the project relies on a network of scientists, neurosurgeons and patients who are willing to donate brain tissue removed during surgery. The ultimate aim is to answer one of the biggest questions in neuroscience: What makes us human?

The answer won’t be simple. But already, the project has turned up hints about what makes the human brain so powerful. Live-tissue experiments have revealed cellular quirks that may be specific to primates and have turned up new details about a mysterious type of nerve cell, or neuron. Other tantalizing discoveries show that humans and mice have very similar numbers of neuron types. This kind of detailed cellular reckoning is a necessary early step on the path to understanding human thoughts, behaviors and abilities.

 “We want a complete description of all the types of neurons,” says Christof Koch, chief scientist and president of the Allen Institute for Brain Science. Steady progress over the last six years shows that answers are within reach. Once order is given to the tangle of neurons that populate our brains, scientists can turn their sights to the bigger mysteries, like how those cells create our memories, emotions and even consciousness itself.

On the morning of May 14, I waited outside of a basement operating room at the University of Washington’s Harborview Medical Center. Inside, a neurosurgeon was cutting deep into the woman’s brain. At 10:15, the wide swinging doors opened, and a doctor carried out a clear plastic jar with an orange cap.

Settled at the bottom of the liquid inside was a bit of brain, gently sloshing around with the motion. Tissue-procurement team member Tamara Casper was ready with a cart that carried a blue cooler (the same kind I have in my garage) on the top and two gas canisters below. The piece of brain had tinged the clear solution pink.

It was a colorful reminder that this tissue had, minutes earlier, been inside a skull, where it was helping to create a woman’s mind.

Scientists have other methods to mimic human brains: Brain organoids , small balls of neural tissue that are grown from stem cells ( SN: 3/3/18, p. 22 ), and animals raised in labs have been immensely helpful to neuroscientists. “There’s real value there,” says Allen Institute neurobiologist Ed Lein. “But what they’re not good for is studying the specifics of the final product in the mature brain.”

This particular sample submerged in the pink liquid had spent 41 years piloting a woman’s life. “It’s hard to emphasize how different this is,” Lein says of the project. Other laboratories have studied live tissue removed from human brains, but none have scaled up and systematized the process as much as this group in Seattle. 

“To me, it’s almost mind-blowing that we can study the human brain outside of the human brain,” says Ryder Gwinn, a neurosurgeon at Swedish Medical Center in Seattle who collaborates with Allen Institute scientists.

Gwinn treats people with epilepsy. Medication doesn’t always stop his patients’ seizures. In severe cases, surgery can be a patient’s best bet. In some of these operations, a surgeon cuts away healthy brain tissue to reach the spot deeper in the brain where seizures first spark. Surgeons peel away the skin and remove a cookie-shaped piece of skull, exposing the temporal lobe of the brain, a stretch of the outermost layer called the cortex. Often, a large piece of the temporal lobe comes out, Gwinn says. Some of that neural tissue goes to pathologists. The rest is typically tossed as medical waste — unless Allen Institute scientists can get their hands on it.

“The tissue is terribly scarce,” Koch says. Early on, colleagues, including many Allen Institute researchers, were skeptical that enough samples could be found and brought to the lab in good shape. But after about 140 surgeries, more than 30 this year alone, it’s clear that these brain samples survive the journey beautifully.

As soon as the sample came out of the OR, Casper hooked up the oxygen and carbon dioxide gas to keep the tissue alive in the liquid, an artificial cerebrospinal fluid. Then she was off, pushing the cart through the hospital with one hand and texting the Allen Institute team with the other. The cart was loaded into a white van modified to safely hold combustible gas canisters. And with that, the bubbling brain bit was on its way. The van threaded through heavy, rain-soaked Seattle traffic back to the lab, where Dee was ready, scalpel in hand.  

After that frustrating start with the uncooperative piece of brain, Dee finally gets enough slices for multiple experiments. A one-hour rest helps the cells recover from the trauma of being separated from the brain. The slices go up to a second-floor lab, where some slices are placed under a powerful microscope and prodded with electricity to study how these live human cells behave. The researchers hope the behavior mimics what the cells did while they were inside their former owner’s skull.

Six scientists sit at “rigs,” each one a microscope mounted inside a black three-sided box. At each rig, a researcher hunts through the woman’s brain tissue for healthy cells — nice and plump, with just the right amount of visibility against the background tissue.

Once they find a good one, the researchers try to latch on with an impossibly thin tube of glass. Called patch-clamp, the technique forces a cellular conversation, which is carried out with electrical signals that move between cells. To get the conversation going requires injecting an electric current into a cell, and then measuring how the cell responds to the artificial message.

Most of these rigs measure the reactions of one neuron at a time. But in the back part of the lab, researcher Lisa Kim pilots a futuristic setup of glistening metal, tangles of blue and black wires and eight needle mounts, all pointing at a different part of a brain slice. While I’m there, this mega-rig is eavesdropping on a kind of party line between seven live neurons. Kim is zipping electricity into each one in turn to see how the signal transmits to its neural neighbors.

The electrical zings of these neurons offer clues about their identities and their relationships; one of the seven cells responds when a neighboring cell gets an electrical zap, a hint that those cells communicated while inside the woman’s head. Other clues come from information about the neurons’ elaborate, gangly shapes created by the signal-sending axons and receiving dendrites. Each neuron reminds me of an impossibly complex map of river tributaries.

An even stronger sense of a cell’s function comes at the end of the patch-clamp experiments. Working the thin glass tube again, a researcher can suck out the nucleus of each live cell. The theft kills the cell but obtains a record of which genes were active when the cell was alive. After Kim finished the game of electrical telephone, she carefully slurped out the nucleus from each of the seven neurons.

All the information gathered from these rigs can help researchers identify neurons that might play a special role in making the human mind. Such scrutiny, for instance, revealed what researchers think is a rare cell called a von Economo neuron, named for the Austrian neurologist who first described the cell type in the 1920s.

The extra-long, extra-spindly neuron was found in live brain tissue donated by a 68-year-old woman who had surgery to remove a tumor. The neuron displayed an unusual electrical response to the current applied to it , Allen Institute scientists and colleagues reported online May 7 at bioRxiv.org. The result was tantalizing, because problems with von Economo neurons are suspected of playing a role in psychiatric conditions and Alzheimer’s disease.

Studies on live human cells also turned up an important difference between humans and mice: A certain kind of human neuron is covered with a protein called an h-channel; in mice, those channels are rare. H-channels help cells respond to electrical signals and can be affected by drugs, including one for epilepsy.

This basic difference, described in 2018 in Neuron , might explain why certain kinds of drugs work differently in the brains of mice and people . More broadly, these newly discovered properties of human neurons might be the things that enable some of the most sophisticated features of our brains.

Taking stock of live human neurons “is essential,” and not just to satisfy humans’ navel-gazing curiosity, says Nenad Sestan, a Yale School of Medicine neuroscientist. Discovering the quirks of human brains “might lead to us understanding one day why we suffer from certain disorders,” Sestan says. Imprecise animal models have stymied research on schizophrenia, autism and Alzheimer’s disease, he says. That’s why studying live, human tissue is so crucial.

From brain to lab

Allen Institute scientists fly into action when a brain sample arrives from a nearby hospital, wringing as much information as they can out of the precious tissue. What the researchers learn about the cells’ behavior, shape and genetic activity is shared publicly in the Allen Brain Atlas. (Bold text shows each step’s duration).

1 to 3 minutes Surgery:   Brain tissue is removed at a Seattle hospital — usually within minutes of a surgeon opening the patient’s skull — and placed into a jar with chilled artificial cerebrospinal fluid bubbling with oxygen and carbon dioxide.

15 to 30 minutes Transport: A specially equipped van speeds the tissue from the hospital to the Allen Institute.

30 to 60 minutes Slice:   The sample is placed on a dish in a bucket of ice, trimmed and sliced into anywhere from six to more than 30 flakes that are each 0.35 millimeters thick.

Distribute:   From each sample, one slice goes into the freezer for future analyses. Every fifth slice is fixed in preservative. The rest are kept alive for more same-day experiments.

1 hour Rest: Live cells recover from the trauma of surgery.

Observe behavior:   Rested cells move to the electrophysiology lab, where “rig” operators study cell behavior with 30 minutes of electrical prodding.

Map cell shape:   Filling some neurons with dye, researchers can see the elaborate projections.

Study the genes:   Thin glass pipettes pull out the nucleus of some neurons so researchers can see which genes were active just before the cells died. 

Weeks to months Manipulation:   Other tests attempt to insert genetic material into cells that stay alive longer than expected. The cells glow for better visibility.

A blow to the ego

But human brains aren’t always so unique. A new result might disappoint people who think that our brains are teeming with specialized neurons that let us talk and think in ways other animals can’t. The overall number of cell types in the human cortex and in the mouse cortex is roughly the same, says a study led by Allen Institute researchers that is in press at Nature . Koch calls the finding “the biggest result, to my mind.”

“People, including scientists, have this strong need [for] human exceptionalism,” Koch says. But the fact that the overall resident population of the human brain and mouse brain is remarkably similar — based on brain tissue from surgeries as well as postmortem tissue — adds to the list of blows to the human ego.

First, Darwin downgraded humans to just another animal on the tree of life. Then, the Human Genome Project shocked us with the news that we have a similar number of genes as mice (and fewer than water fleas). Now, add brain cell types to the list of things that make people more like other mammals. 

The paper coming out in Nature is “historic,” says coauthor Rafael Yuste, a neuroscientist at Columbia University. In terms of understanding how humans compare with other animals, “it’s going to be a before-this and after-this.”

These similarities don’t surprise Suzana Herculano-Houzel, a neurobiologist at Vanderbilt University in Nashville. “We are not special,” she says. Finding that humans and mice have similar types of cells in their brains makes a lot of sense, as does the idea that some cell types and some genes will be species-specific. The question is, she says: “Which of those differences are actually meaningful?”

The explanation for why we’re so smart, then, is not that our brains are teeming with specialized, human-specific neurons. The answer must be found elsewhere. Perhaps it really is in small numbers of rare neurons such as von Economo neurons, or in neurons that haven’t yet been discovered. Still other scientists think that our brainpower might come, in part, from cells in the brain that aren’t neurons, such as the glial cells that perform a range of basic brain jobs that scientists are just beginning to understand ( SN: 8/22/15, p. 18 ).

Or maybe, as Yuste suspects, the answer is the sheer size of our brains compared with our relatively small bodies. Or perhaps our “smarts” are a result of our long life span and the fact that we are immersed in cultures rich with language, literature and customs, as Herculano-Houzel points out.

As Dee did his slicing, neurobiologist Jonathan Ting waited eagerly for his bit of brain. Ting runs experiments that deliver genes to live cells — and he’s kept his cells alive a surprisingly long time.

In his fourth-floor lab, Ting is not happy with the piece he got, calling it “kind of a bloody mess.” But he cuts it up some more and returns the resulting slices to the bubbling solution. Then he pulls what looks like a baking tray out of a nearby incubator, makes a Martha Stewart joke and shows me live brain samples that are weeks old. Some have survived for several months, a hardiness that shocked the researchers when they first began these experiments.

This kind of durability comes in handy as Ting tinkers with how best to infect the cells with viruses. His goal is to use the viruses to deliver genes that make certain groups of live human cells glow. The glow makes it easier to study the cells and, ultimately, to figure out how to change their behavior. To Ting’s delight, he discovered that the virus and its luminescent cargo can be delivered simply by dropping virus-laden liquid on the live brain slices.

As Ting and I look at glowing red and green cells on his microscope’s monitor, he describes the potential of this work with viruses. Not only will the researchers be able to find rare cells in human brains, but they might be able to ultimately control the cells, too. Imagine if a von Economo cell, for instance, could be turned on and off at will with methods that are already under development in animal models.

If the cells are actually involved in a disorder, say, schizophrenia, then this sort of precise control could lead to a targeted treatment that toggles the cells’ activity up or down as needed. It could also ultimately reveal how information flows through these cells, in a way that makes up the mind.

All this tinkering has already turned up big findings. But there is vastly more uncharted territory to explore, Koch says. “The brain is by far, by far the most complex, highly organized piece of active matter anywhere in the universe.”

About this story

Where did the idea come from.

I heard about this project about five years ago at the meeting of the Society for Neuroscience. It wasn’t clear then if the effort would pay off. But with over 100 surgeries and a handful of research papers published, it felt like the story was ripe.

How are we reporting this story?

I had hoped to talk patients and watch surgeries. But that meant getting permission from doctors, hospital administrators, and most importantly, the patient. After several failed attempts, I decided to tell the story with the brain sample itself taking center stage.

I live about four hours south of Seattle. When I got the call that surgery was happening the next morning, I hopped in the car and arrived late that night. I was at Harborview Medical Center just after 9 am to follow a sample of live brain tissue from an operating room to labs across town at the Allen Institute for Brain Science.

I had expected to see frantic speed as scientists raced to study still-living tissue. But I was struck by how much of the process was calm. It was clear that these researchers knew exactly what they needed to do.

— Laura Sanders

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Ideas for Psychology Experiments

Inspiration for psychology experiments is all around if you know where to look

Psychology experiments can run the gamut from simple to complex. Students are often expected to design—and sometimes perform—their own experiments, but finding great experiment ideas can be a little challenging. Fortunately, inspiration is all around if you know where to look—from your textbooks to the questions that you have about your own life.

Always discuss your idea with your instructor before beginning your experiment—particularly if your research involves human participants. (Note: You'll probably need to submit a proposal and get approval from your school's institutional review board.)

At a Glance

If you are looking for an idea for psychology experiments, start your search early and make sure you have the time you need. Doing background research, choosing an experimental design, and actually performing your experiment can be quite the process. Keep reading to find some great psychology experiment ideas that can serve as inspiration. You can then find ways to adapt these ideas for your own assignments.

15 Ideas for Psychology Experiments

Most of these experiments can be performed easily at home or at school. That said, you will need to find out if you have to get approval from your teacher or from an institutional review board before getting started.

The following are some questions you could attempt to answer as part of a psychological experiment:

• Are people really able to "feel like someone is watching" them ? Have some participants sit alone in a room and have them note when they feel as if they are being watched. Then, see how those results line up to your own record of when participants were actually being observed.
• Can certain colors improve learning ? You may have heard teachers or students claim that printing text on green paper helps students read better, or that yellow paper helps students perform better on math exams. Design an experiment to see whether using a specific color of paper helps improve students' scores on math exams.
• Can color cause physiological reactions ? Perform an experiment to determine whether certain colors cause a participant's blood pressure to rise or fall.
• Can different types of music lead to different physiological responses ? Measure the heart rates of participants in response to various types of music to see if there is a difference.
• Can smelling one thing while tasting another impact a person's ability to detect what the food really is ? Have participants engage in a blind taste test where the smell and the food they eat are mismatched. Ask the participants to identify the food they are trying and note how accurate their guesses are.
• Could a person's taste in music offer hints about their personality ? Previous research has suggested that people who prefer certain styles of music tend to exhibit similar  personality traits. Administer a personality assessment and survey participants about their musical preferences and examine your results.
• Do action films cause people to eat more popcorn and candy during a movie ? Have one group of participants watch an action movie, and another group watch a slow-paced drama. Compare how much popcorn is consumed by each group.
• Do colors really impact moods ? Investigate to see if the  color blue makes people feel calm, or if the color red leaves them feeling agitated.
• Do creative people see  optical illusions  differently than more analytical people ? Have participants complete an assessment to measure their level of creative thinking. Then ask participants to look at optical illusions and note what they perceive.
• Do people rate individuals with perfectly symmetrical faces as more beautiful than those with asymmetrical faces ? Create sample cards with both symmetrical and asymmetrical faces and ask participants to rate the attractiveness of each picture.
• Do people who use social media exhibit signs of addiction ? Have participants complete an assessment of their social media habits, then have them complete an addiction questionnaire.
• Does eating breakfast help students do better in school ? According to some, eating breakfast can have a beneficial influence on school performance. For your experiment, you could compare the test scores of students who ate breakfast to those who did not.
• Does sex influence short-term memory ? You could arrange an experiment that tests whether men or women are better at remembering specific types of information.
• How likely are people to conform in groups ? Try this experiment to see what percentage of people are likely to conform . Enlist confederates to give the wrong response to a math problem and then see if the participants defy or conform to the rest of the group.
• How much information can people store in short-term memory ? Have participants study a word list and then test their memory. Try different versions of the experiment to see which memorization strategies, like chunking or mnemonics, are most effective.

Once you have an idea, the next step is to learn more about  how to conduct a psychology experiment .

Psychology Experiments on Your Interests

If none of the ideas in the list above grabbed your attention, there are other ways to find inspiration for your psychology experiments.

How do you come up with good psychology experiments? One of the most effective approaches is to look at the various problems, situations, and questions that you are facing in your own life.

You can also think about the things that interest you. Start by considering the topics you've studied in class thus far that have really piqued your interest. Then, whittle the list down to two or three major areas within psychology that seem to interest you the most.

From there, make a list of questions you have related to the topic. Any of these questions could potentially serve as an experiment idea.

Use Textbooks for Inspiration for Psychology Experiments

Your psychology textbooks are another excellent source you can turn to for experiment ideas. Choose the chapters or sections that you find particularly interesting—perhaps it's a chapter on  social psychology  or a section on child development.

Start by browsing the experiments discussed in your book. Then think of how you could devise an experiment related to some of the questions your text asks. The reference section at the back of your textbook can also serve as a great source for additional reference material.

Discuss Psychology Experiments with Other Students

It can be helpful to brainstorm with your classmates to gather outside ideas and perspectives. Get together with a group of students and make a list of interesting ideas, subjects, or questions you have.

The information from your brainstorming session can serve as a basis for your experiment topic. It's also a great way to get feedback on your own ideas and to determine if they are worth exploring in greater depth.

Study Classic Psychology Experiments

Taking a closer look at a classic psychology experiment can be an excellent way to trigger some unique and thoughtful ideas of your own. To start, you could try conducting your own version of a famous experiment or even updating a classic experiment to assess a slightly different question.

Famous Psychology Experiments

Examples of famous psychology experiments that might be a source of further questions you'd like to explore include:

• Marshmallow test experiments
• Little Albert experiment
• Hawthorne effect experiments
• Bystander effect experiments
• Robbers Cave experiments
• Halo effect experiments
• Piano stairs experiment
• Cognitive dissonance experiments
• False memory experiments

You might not be able to replicate an experiment exactly (lots of classic psychology experiments have ethical issues that would preclude conducting them today), but you can use well-known studies as a basis for inspiration.

Review the Literature on Psychology Experiments

If you have a general idea about what topic you'd like to experiment, you might want to spend a little time doing a brief literature review before you start designing. In other words, do your homework before you invest too much time on an idea.

Visit your university library and find some of the best books and articles that cover the particular topic you are interested in. What research has already been done in this area? Are there any major questions that still need to be answered? What were the findings of previous psychology experiments?

Tackling this step early will make the later process of writing the introduction  to your  lab report  or research paper much easier.

Ask Your Instructor About Ideas for Psychology Experiments

If you have made a good effort to come up with an idea on your own but you're still feeling stumped, it might help to talk to your instructor. Ask for pointers on finding a good experiment topic for the specific assignment. You can also ask them to suggest some other ways you could generate ideas or inspiration.

While it can feel intimidating to ask for help, your instructor should be more than happy to provide some guidance. Plus, they might offer insights that you wouldn't have gathered on your own. Your instructor probably has lots of ideas for psychology experiments that would be worth exploring.

If you need to design or conduct psychology experiments, there are plenty of great ideas (both old and new) for you to explore. Consider an idea from the list above or turn some of your own questions about the human mind and behavior into an experiment.

Before you dive in, make sure that you are observing the guidelines provided by your instructor and always obtain the appropriate permission before conducting any research with human or animal subjects.

Frequently Asked Questions

Finding a topic for a research paper is much like finding an idea for an experiment. Start by considering your own interests, or browse though your textbooks for inspiration. You might also consider looking at online news stories or journal articles as a source of inspiration.

Three of the most classic social psychology experiments are:

• The Asch Conformity Experiment : This experiment involved seeing if people would conform to group pressure when rating the length of a line.
• The Milgram Obedience Experiment : This experiment involved ordering participants to deliver what they thought was a painful shock to another person.
• The Stanford Prison Experiment : This experiment involved students replicating a prison environment to see how it would affect participant behavior. 

Jakovljević T, Janković MM, Savić AM, et al. The effect of colour on reading performance in children, measured by a sensor hub: From the perspective of gender .  PLoS One . 2021;16(6):e0252622. doi:10.1371/journal.pone.0252622

Greenberg DM, et al. Musical preferences are linked to cognitive styles . PLoS One. 2015;10(7). doi:10.1371/journal.pone.0131151

Kurt S, Osueke KK. The effects of color on the moods of college students . Sage. 2014;4(1). doi:10.1177/2158244014525423

Hartline-Grafton H, Levin M. Breakfast and School-Related Outcomes in Children and Adolescents in the US: A Literature Review and its Implications for School Nutrition Policy .  Curr Nutr Rep . 2022;11(4):653-664. doi:10.1007/s13668-022-00434-z

By Kendra Cherry, MSEd Kendra Cherry, MS, is a psychosocial rehabilitation specialist, psychology educator, and author of the "Everything Psychology Book."

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• 25 April 2018

The ethics of experimenting with human brain tissue

• Nita A. Farahany 0 ,
• Henry T. Greely 1 ,
• Steven Hyman 2 ,
• Christof Koch 3 ,
• Christine Grady 4 ,
• Sergiu P. Pașca 5 ,
• Nenad Sestan 6 ,
• Paola Arlotta 7 ,
• James L. Bernat 8 ,
• Jonathan Ting 9 ,
• Jeantine E. Lunshof 10 ,
• Eswar P. R. Iyer 11 ,
• Insoo Hyun 12 ,
• Beatrice H. Capestany 13 ,
• George M. Church 14 ,
• Hao Huang 15 &
• Hongjun Song 16

Nita A. Farahany is professor of law and philosophy at Duke University, director of the Duke Initiative for Science & Society, Duke University, Durham, North Carolina, USA.

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Henry T. Greely is professor of law, director of the Center for Law and the Biosciences, and director of the Stanford Program in Neuroscience and Society at Stanford University, California, USA.

Steven Hyman is director of the Stanley Center for Psychiatric Research at the Broad Institute of MIT and Harvard University; and Harvard University distinguished service professor in the Department of Stem Cell and Regenerative Biology at Harvard University, Cambridge, Massachusetts, USA.

Christof Koch is the chief scientist and president at the Allen Institute for Brain Science, Seattle, Washington, USA.

Christine Grady is chief of the Department of Bioethics at the National Institutes of Health Clinical Center, Bethesda, Maryland, USA.

Sergiu P. Pașca is assistant professor of psychiatry and behavioural sciences at Stanford University, Palo Alto, California, USA.

Nenad Sestan is professor of neuroscience, of genetics, of psychiatry, and of comparative medicine at the Yale School of Medicine, New Haven, Connecticut, USA.

Paola Arlotta is professor of stem cell and regenerative biology at Harvard University, Cambridge, Massachusetts, USA.

James L. Bernat is professor of neurology and medicine (active emeritus) at the Geisel School of Medicine at Dartmouth in Hanover, New Hampshire, USA.

Jonathan Ting is assistant investigator at the Allen Institute for Brain Science, Seattle, Washington, USA.

Jeantine E. Lunshof is research scientist-ethicist at MIT Media Lab in Cambridge, Massachusetts; ethics consultant to the Department of Genetics at Harvard Medical School, Boston, Massachusetts, USA; assistant professor in the Department of Genetics, University of Groningen, Groningen, the Netherlands.

Eswar P. R. Iyer is a postdoctoral fellow at Harvard Medical School and the Wyss Institute for Biologically Inspired Engineering at Harvard University.

Insoo Hyun is associate professor of bioethics and philosophy at Case Western Reserve University School of Medicine, Cleveland, Ohio, USA.

Beatrice H. Capestany is a postdoctoral fellow at the Science, Law, and Policy Lab at the Duke Initiative for Science & Society, Duke University, Durham, North Carolina, USA.

George M. Church is professor of genetics at Department of Genetics, Harvard Medical School, and Wyss Institute for Biologically Inspired Engineering, Boston, Massachusetts, USA.

Hao Huang is associate professor of radiology at University of Pennsylvania, Philadelphia, USA.

Hongjun Song is Perelman professor of neuroscience at University of Pennsylvania in Philadelphia, USA.

If researchers could create brain tissue in the laboratory that might appear to have conscious experiences or subjective phenomenal states, would that tissue deserve any of the protections routinely given to human or animal research subjects?

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History of Now

The True Story of Brainwashing and How It Shaped America

Fears of Communism during the Cold War spurred psychological research, pop culture hits, and unethical experiments in the CIA

Lorraine Boissoneault

Journalist Edward Hunter was the first to sound the alarm. “Brain-washing Tactics Force Chinese Into Ranks of Communist Party,” blared his headline in the Miami Daily News in September 1950. In the article, and later in a book, Hunter described how Mao Zedong’s Red Army used terrifying ancient techniques to turn the Chinese people into mindless, Communist automatons. He called this hypnotic process “brainwashing,” a word-for-word translation from xi-nao, the Mandarin words for wash ( xi ) and brain ( nao ), and warned about the dangerous applications it could have. The process was meant to “ change a mind radically so that its owner becomes a living puppet—a human robot—without the atrocity being visible from the outside.”

It wasn’t the first time fears of Communism and mind control had seeped into the American public. In 1946 the U.S. Chamber of Commerce was so worried about the spread of Communism that it proposed removing liberals, socialists and communists from places like schools, libraries, newspapers and entertainment. Hunter’s inflammatory rhetoric didn’t immediately have a huge impact—until three years into the Korean War, when American prisoners of war began confessing to outlandish crimes.

When he was shot down over Korea and captured in 1952, Colonel Frank Schwable was the highest ranking military officer to meet that fate, and by February 1953, he and other prisoners of war had falsely confessed to using germ warfare against the Koreans, dropping everything from anthrax to the plague on unsuspecting civilians. The American public was shocked, and grew even more so when 5,000 of the 7,200 POWs either petitioned the U.S. government to end the war, or signed confessions of their alleged crimes. The final blow came when 21 American soldiers refused repatriation.

Suddenly the threat of brainwashing was very real, and it was everywhere. The U.S. military denied the charges made in the soldiers’ “confessions,” but couldn’t explain how they’d been coerced to make them. What could explain the behavior of the soldiers besides brainwashing? The idea of mind control flourished in pop culture, with movies like Invasion of the Body Snatchers and The Manchurian Candidate showing people whose minds were wiped and controlled by outside forces. FBI director J. Edgar Hoover referred to thought-control repeatedly in his book Masters of Deceit: The Story of Communism in America and How to Fight It . By 1980 even the American Psychiatric Association had given it credence, including brainwashing under “dissociative disorders” in the Diagnostic and Statistical Manual of Mental Disorders-III. Had Chinese and Soviet Communists really uncovered a machine or method to rewrite men’s minds and supplant their free will?

The short answer is no—but that didn’t stop the U.S. from pouring resources into combatting it.

“The basic problem that brainwashing is designed to address is the question ‘why would anybody become a Communist?’” says Timothy Melley, professor of English at Miami University and author of The Covert Sphere: Secrecy, Fiction, and the National Security State . “[Brainwashing] is a story that we tell to explain something we can’t otherwise explain.”

The term had multiple definitions that changed depending on who used it. For Hunter—who turned out to be an agent in the CIA’s propaganda wing—it was a mystical, Oriental practice that couldn’t be understood or anticipated by the West, Melley says. But for scientists who actually studied the American POWs once they returned from Korea, brainwashing was altogether less mysterious than the readily apparent outcome: The men had been tortured.

Robert Jay Lifton, one of the psychiatrists who worked with the veterans and later studied doctors who aided Nazi war crimes, listed eight criteria for thought reform (the term for brainwashing used by Mao Zedong's communist government). They included things like “milieu control” (having absolute power over the individual’s surroundings) and “confession” (in which individuals are forced to confess to crimes repeatedly, even if they aren’t true). For the American soldiers trapped in the Korean prison camps, brainwashing meant forced standing, deprivation of food and sleep, solitary confinement, and repeated exposure to Communist propaganda.

“There was concern on the part of [the American military] about what had actually happened to [the POWs] and whether they had been manipulated to be [what would later be known as] a ‘Manchurian candidate,’” says Marcia Holmes, a science historian at the University of London’s “ Hidden Persuaders ” project. “They’re not sleeper agents, they’re just extremely traumatized.”

The early 1950s marked the debut of the military’s studies into psychological torture, and instead of concluding the American soldiers needed rehabilitation, military directors came to a more ominous conclusion: that the men were simply weak. “They became less interested in the fantasy of brainwashing and became worried our men couldn’t stand up to torture,” Holmes says. This resulted in the Survival, Evasion, Resistance, Escape program (SERE), meant to inoculate men against future attempts at psychological torture by using those same torture techniques in their training.

Meanwhile, the American public was still wrapped up in fantasies of hypnotic brainwashing, in part due to the research of pop psychologists like Joost Meerloo and William Sargant. Unlike Lifton and the other researchers hired by the military, these two men portrayed themselves as public intellectuals and drew parallels between brainwashing and tactics used by both American marketers and Communist propagandists. Meerloo believes that “totalitarian societies like Nazi Germany and the Soviet Union or Communist China were in the past, and continue to be, quite successful in their thought-control programs… [and] the more recently available techniques of influence and thought control are more securely based on scientific fact, more potent and more subtle,” writes psychoanalyst Edgar Schein in a 1959 review of Meerloo’s book, The Rape of the Mind: The Psychology of Thought Control—Menticide and Brainwashing .

Psychiatrists, as well as writers like Aldous Huxley, were aided by the dominant theory of the human mind at the time, known as “behaviorism”. Think of Ivan Pavlov’s slobbering dogs, trained to salivate upon hearing a bell, even if they weren’t tempted with food. The basic assumption of behaviorism was that the human mind is a blank slate at birth, and is shaped through social conditioning throughout life. Where Russia had Pavlov, the U.S. had B.F. Skinner , who suggested psychology could help predict and control behavior. Little wonder, then, that the public and the military alike couldn’t let go of brainwashing as a concept for social control.  

With this fear of a mind-control weapon still haunting the American psyche, CIA director Allen Dulles authorized a series of psychological experiments using hallucinogens (like LSD) and biological manipulation (like sleep deprivation) to see if brainwashing were possible. The research could then, theoretically, be used in both defensive and offensive programs against the Soviet Union. Project MK-ULTRA began in 1953 and continued in various forms for more than 10 years. When the Watergate scandal broke, fear of discovery led the CIA to destroy most of the evidence of the program. But 20,000 documents were recovered through a Freedom of Information Act request in 1977 , filed during a Senate investigation into Project MK-ULTRA. The files revealed the experiments tested drugs (like LSD), sensory deprivation, hypnotism and electroshock on everyone from agency operatives to prostitutes, recovering drug addicts and prisoners—often without their consent.

Despite MK-ULTRA violating ethical norms for human experiments, the legacy of brainwashing experiments continued to live on in U.S. policy. The same methods that had once been used to train American soldiers ended up being used to extract information from terrorists in Abu Ghraib, Iraq and Guantanamo Bay .

“Here, then, is the brief history of brainwashing,” Melley writes in a 2011 paper for Grey Room . “The concept began as an [O]rientalist propaganda fiction created by the CIA to mobilize domestic support for a massive military build-up. This fiction proved so effective that the CIA’s operations directorate believed it and began a furious search for a real mind control weapon. The search resulted not in a miraculous new weapon but a program of simulated brainwashing designed as a prophylactic against enemy mistreatment. This simulation in turn became the real basis for interrogating detainees in the war on terror.”

While few people take seriously the notion of hypnosis-like brainwashing (outside Hollywood films like Zoolander ), there are still plenty who see danger in certain kinds of control. Consider the conversations about ISIS and radicalization, in which young people are essentially portrayed as being brainwashed. “Can You Turn a Terrorist Back Into a Citizen? A controversial new program aims to reform homegrown ISIS recruits back into normal young Americans,” proclaims one article in Wired . Or there’s the more provocative headline from Vice : “ Inside the Mind-Control Methods the Islamic State Uses to Recruit Teenagers .”

“I think a program of isolation and rigorous conversion still does have a life in our concept of radicalization,” Melley says. But outside those cases related to terrorism it’s mostly used facetiously, he adds.  

“The notion of brainwashing, no less than radicalization, often obscure[s] far more than it reveal[s],” write Sarah Marks and Daniel Pick of the Hidden Persuaders project. “Both terms could be a lazy way of refusing to inquire further into individual histories, inviting the assumption that the way people act can be known in advance.”

For now, the only examples of “perfect” brainwashing remain in science-fiction rather than fact. At least until researchers find a way to hack into the network of synapses that comprise the brain .

Editor's note, May 25, 2017: The article previously misstated that Robert Jay Lifton studied Nazi doctors' war crimes before studying American prisoners of war, and that he coined the term "thought reform." 

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Lorraine Boissoneault is a contributing writer to SmithsonianMag.com covering history and archaeology. She has previously written for The Atlantic, Salon, Nautilus and others. She is also the author of The Last Voyageurs: Retracing La Salle's Journey Across America. Website: http://www.lboissoneault.com/

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10 Psychological Experiments That Will Blow Your Mind

The study of the human mind is fascinating. Understanding why we behave in the way we do could be the key to unleashing the full potential of the human race. So it is inevitable, perhaps, that researchers push at the boundaries of acceptability when devising psychological experiments .

Sometimes though, they go too far, and their eagerness to understand comes at the expense of other people’s safety and well-being. At best, the following psychological experiments left their participants hurt and upset (and sometimes traumatized). At worst, they cost lives.

10 The Monster Experiment

Ten of the 22 children had preexisting stammers, and the other 12 had no speech impediments. Half of those with stutters were repeatedly told that their speech was fine to see whether this cured them. It didn’t. The 12 normal-speaking children were divided into two groups. Half were told that their speech was normal and the other half that they had an impediment, despite their speech actually being normal.

This latter group did not produce stammerers, as Johnson had expected, but exhibited severe anxiety with lasting effects. Uneasy, Mary Tudor went back to the orphanage to try to undo the damage, but it was too late. One of her subjects wrote to her and called her a monster , saying, “I remember your face, how kind you were and you looked like my mother, but you were there to destroy my life.”

9 The Stanford Prison Experiment

The Stanford Prison Experiment was both masterful and deeply disturbing.

In 1971, Professor Philip Zimbardo constructed a mock prison and recruited students to play the parts of guards and prisoners in an effort to discover whether the brutality experienced by convicts in American prisons was the result of the prison conditions or the personalities of the wardens and convicts.

The 24 participants were randomly assigned the role of prisoner or guard. Prisoners were arrested without warning, fingerprinted, and blindfolded before being driven to the makeshift prison, where they were stripped naked, “deloused,” and given uniforms with their prison number on. Guards wore military-style uniforms and dark glasses and carried whistles and wooden clubs. The guards were instructed to do whatever they thought necessary to control the inmates.

Within hours, the guards and prisoners began to behave confrontationally. Guards imposed punishments, raided cells, and woke prisoners up for roll call during the night. On day two, the prisoners rebelled, barricading themselves in their cells with their beds. Guards called for reinforcements, sprayed fire extinguishers at the prisoners, stripped them naked, and removed their beds from their cells.

After their initial rebellion, the prisoners became more submissive, but the guards’ aggression increased. The experiment was due to last two weeks, but so great was the change in behavior that the study was abandoned after five days for fear of injury and long-term damage to participants. [2]

8 UCLA Schizophrenia Experiments

Antonio Lamadrid was one of the subjects for several years. After being well for a year, his medication was reduced. He quickly became ill and talked of suicide. Lamadrid killed himself in 1991 by jumping from the roof of a UCLA building. [3]

Antonio Lamadrid’s death raised the question of informed consent among the mentally ill. A lawsuit found the university not responsible for Lamadrid’s death but concluded that they had violated key aspects of informed consent rules governing experimentation on human subjects.

7 Little Albert

In the late 1910s, behavioral scientist John B. Watson was studying whether emotional reactions could be conditioned in humans, after the manner of Pavlov’s dogs. One of his subjects was a baby named Albert, aged nine months. Albert was exposed to a series of stimuli, including a white rat, a rabbit, a monkey, masks, and burning newspapers. Initially, Albert showed no fear of any of these objects.

Then, as Albert was exposed to the rat, Watson made a loud noise by hitting a metal pipe with a hammer , whereupon Albert cried. After being repeatedly presented the white rat followed by the loud noise, Albert began to cry as soon as he saw the rat.

Watson must have conducted the experiment many times because he collected enough data to discover that not only did the kid cry at white rats, but he also began to cry at anything that might possibly look like a rat, including a variety of white objects and an equally large assortment of furry objects (including, at one point, a Santa Claus beard). [4] Even those objects which he had previously played with began to frighten him if they bore any resemblance to a rat (or if they were handed to him by a man wielding a hammer).

Watson didn’t bother to decondition Little Albert at the end of the experiment, and it is unknown whether his fear of vermin, loud noises, or psychologists remained with him. Sadly, Albert died at the age of six. It is unknown whether his mother, who was paid a grand total of $1 for his participation, ever realized what it was they were doing when they came to play with her son.

6 Lost In A Mall

Participants in the study believed that they were taking part in an experiment about childhood memories. They and their relatives were asked to provide stories. A booklet was presented to the subject recounting three true memories and a false one supposedly provided by the relative. The subjects were then asked to contribute their memory of the incident and to say if they didn’t remember it.

Further interviews over the following weeks discussed the fictional incident, until finally subjects were asked to say how well they remembered being lost in the mall. [5]

In many cases, it was noticed that the false memories were actually clearer and more “real” than the genuine ones. Loftus’s work appeared to prove that it is possible to recover memories of things that never happened, though, of course, this doesn’t prove that it isn’t also possible to repress and then uncover memories of things that did happen, which just goes to show that the brain is a tricky thing.

5 The Bystander Effect

In order to test their hypothesis, Latane and Darley conducted an experiment where students were sometimes alone, and sometimes in groups of varying size, when an actor pretended to have an epileptic seizure. It was noticed that those students who were alone with the patient sought help 85 percent of the time. (Goodness knows what the other 15 percent did.) But that number decreased to 62 percent and then only 31 percent as the number of other bystanders increased.

The larger the group, the greater the indecision and the more bystanders relied on “someone else” to do something. [6] Unfortunately, researchers do not seem able to find a cure for this kind of paralysis that overcomes people, but thankfully some people are immune. Take Hugo Alfredo Tale-Yax. In early 2010, Yax witnessed a woman being attacked by a man with a knife and stepped in to save her. In the process, he was stabbed several times.

Yax was not as fortunate as the woman he saved. He lay dying on the pavement for more than an hour, while dozens of people walked by. Some people stopped to look at him, and one person even videoed his death. However, by the time someone finally called emergency services, Hugo Yax was dead .

4 Jane Elliot Racism Experiment

In the aftermath of Martin Luther King’s assassination, Elliot decided to deliver a class on racism to her third-grade students. She separated the children by eye color and, citing some spurious science, declared that people with brown eyes were “better” than people with blue eyes.

By lunchtime, the students had formed groups, the blue eyes against the brown eyes, and they began to identify characteristics of blue-eyed people—lazy, stupid, clumsy etc. Blue-eyed students who were normally confident learners suddenly started to make mistakes, and brown-eyed students grew in confidence, at least until the following week, when the situations were reversed. [7]

Elliot has repeated this experiment numerous times in the years since and noticed that when the roles were reversed, the now-dominant students were less judgemental than their classmates, perhaps because they had experienced discrimination and didn’t like it. Elliot’s techniques are not without criticism, and she received much flak from parents who believed that the experiments were cruel “to white children.”

3 Project MKULTRA

Researchers began to look at how to deepen the effects of hypnosis, how to induce amnesia, and which drugs would allow individuals to withstand torture under interrogation. Hmm; wonder how they tested that?

The test subjects were mostly convicts, sex workers, and, most shockingly, the terminally ill. Among other drugs, LSD was given to participants without their knowledge, causing great distress. At least two people died as a result of their participation in the program, and many more were left with lasting aftereffects.

The true scope of the research project may never be known, as thousands of records were destroyed in 1977, and despite an inquiry and several lawsuits, no one has ever been held accountable for the work done on Project MKULTRA. [8]

2 The Robbers Cave Experiment

In 1954, Muzafer Sherif devised an experiment that he hoped would demonstrate how the hostility between different groups could be overcome by working together against a common threat. His first effort was a dismal failure when he took two groups of boys to a summer camp and first tried to get them to work against each other. Having met their enemies, the boys were disposed to like them, and the experiment failed.

He repeated the experiment and took care to ensure that the two groups of boys did not meet until their loyalties were fixed. His theory was that conflict would arise when the groups competed for the same resources. He allowed each group time to bond with their own and then introduced a number of competitive activities that gave special privileges or prizes to the winners. Each group immediately became invested in winning the competition for their “team.”

Following this, Sherif arranged for one team to seem to gain an unfair benefit, such as organizing a picnic where one group arrived first and ate all the food. This increased tensions further, and the boys began to become more aggressive, raiding each others’ tents, stealing each others’ possessions, and intimidating their rivals. They became so physically threatening at one point that the researchers had to separate them. [9]

At this point, Sherif engineered a forest fire and sat back and watched as the boys initially worked in separate groups to put the fire out, before finally coming together to form a human chain to collect water to extinguish it. His experiment was said to have demonstrated “realistic conflict theory.” However, there have been some critics of his test, both because of the lack of informed consent and some evidence that the boys were manipulated in their behavior.

Plus, you know, Sherif lit a forest fire and left 22 kids to get on with putting it out.

1 The Milgram Experiment

In one of the most famous psychological experiments ever, in the early 1960s, Stanley Milgram set out to explore the boundaries between obedience to authority and personal conscience, after watching the Nuremberg Trials, during which former Nazis charged with atrocities claimed that they were just following orders.

He was interested in seeing how far people would obey instructions, even if they involved hurting other people. Subjects were first introduced to their partner in the experiment so that they could meet them as a human being. They were then asked to draw lots to see who was to play the teacher and who was the student . In fact, the “student” was an actor hired for the study.

The teachers were asked to read a series of questions to the student, who was in another room but could be communicated with verbally. The teacher sat in front of a machine with an electric generator and a row of switches marked at increasing voltages from 15 to 450 volts. The teachers were instructed to ask the learners a series of questions and to apply an electric shock each time they got an answer wrong. Each wrong answer meant an increased shock intensity. (The shocks weren’t real, hence the actor.)

All the participants in the trial administered shocks to the “student” of up to 300 volts, and two thirds of them continued all the way to 450 volts despite the fact that the higher voltages were labeled as extremely dangerous. [10]

From his results, Milgram concluded that people are liable to follow orders where they perceive the person giving the instructions to have authority over them, even past the point where their own conscience is telling them they should stop.

Ward Hazell is a writer who travels, and an occasional travel writer.

Read more about the study of the human mind on 10 Common Misconceptions About Psychology and 10 Shocking Myths Of Modern Psychiatry .