experimental meaning in psychology

Experimental Psychology: 10 Examples & Definition

Dave Cornell (PhD)

Dr. Cornell has worked in education for more than 20 years. His work has involved designing teacher certification for Trinity College in London and in-service training for state governments in the United States. He has trained kindergarten teachers in 8 countries and helped businessmen and women open baby centers and kindergartens in 3 countries.

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Experimental psychology refers to studying psychological phenomena using scientific methods. Originally, the primary scientific method involved manipulating one variable and observing systematic changes in another variable.

Today, psychologists utilize several types of scientific methodologies.

Experimental psychology examines a wide range of psychological phenomena, including: memory, sensation and perception, cognitive processes, motivation, emotion, developmental processes, in addition to the neurophysiological concomitants of each of these subjects.

Studies are conducted on both animal and human participants, and must comply with stringent requirements and controls regarding the ethical treatment of both.

Definition of Experimental Psychology

Experimental psychology is a branch of psychology that utilizes scientific methods to investigate the mind and behavior.

It involves the systematic and controlled study of human and animal behavior through observation and experimentation .

Experimental psychologists design and conduct experiments to understand cognitive processes, perception, learning, memory, emotion, and many other aspects of psychology. They often manipulate variables ( independent variables ) to see how this affects behavior or mental processes (dependent variables).

The findings from experimental psychology research are often used to better understand human behavior and can be applied in a range of contexts, such as education, health, business, and more.

Experimental Psychology Examples

1. The Puzzle Box Studies (Thorndike, 1898) Placing different cats in a box that can only be escaped by pulling a cord, and then taking detailed notes on how long it took for them to escape allowed Edward Thorndike to derive the Law of Effect: actions followed by positive consequences are more likely to occur again, and actions followed by negative consequences are less likely to occur again (Thorndike, 1898).

2. Reinforcement Schedules (Skinner, 1956) By placing rats in a Skinner Box and changing when and how often the rats are rewarded for pressing a lever, it is possible to identify how each schedule results in different behavior patterns (Skinner, 1956). This led to a wide range of theoretical ideas around how rewards and consequences can shape the behaviors of both animals and humans.

3. Observational Learning (Bandura, 1980) Some children watch a video of an adult punching and kicking a Bobo doll. Other children watch a video in which the adult plays nicely with the doll. By carefully observing the children’s behavior later when in a room with a Bobo doll, researchers can determine if television violence affects children’s behavior (Bandura, 1980).

4. The Fallibility of Memory (Loftus & Palmer, 1974) A group of participants watch the same video of two cars having an accident. Two weeks later, some are asked to estimate the rate of speed the cars were going when they “smashed” into each other. Some participants are asked to estimate the rate of speed the cars were going when they “bumped” into each other. Changing the phrasing of the question changes the memory of the eyewitness.

5. Intrinsic Motivation in the Classroom (Dweck, 1990) To investigate the role of autonomy on intrinsic motivation, half of the students are told they are “free to choose” which tasks to complete. The other half of the students are told they “must choose” some of the tasks. Researchers then carefully observe how long the students engage in the tasks and later ask them some questions about if they enjoyed doing the tasks or not.

6. Systematic Desensitization (Wolpe, 1958) A clinical psychologist carefully documents his treatment of a patient’s social phobia with progressive relaxation. At first, the patient is trained to monitor, tense, and relax various muscle groups while viewing photos of parties. Weeks later, they approach a stranger to ask for directions, initiate a conversation on a crowded bus, and attend a small social gathering. The therapist’s notes are transcribed into a scientific report and published in a peer-reviewed journal.

7. Study of Remembering (Bartlett, 1932) Bartlett’s work is a seminal study in the field of memory, where he used the concept of “schema” to describe an organized pattern of thought or behavior. He conducted a series of experiments using folk tales to show that memory recall is influenced by cultural schemas and personal experiences.

8. Study of Obedience (Milgram, 1963) This famous study explored the conflict between obedience to authority and personal conscience. Milgram found that a majority of participants were willing to administer what they believed were harmful electric shocks to a stranger when instructed by an authority figure, highlighting the power of authority and situational factors in driving behavior.

9. Pavlov’s Dog Study (Pavlov, 1927) Ivan Pavlov, a Russian physiologist, conducted a series of experiments that became a cornerstone in the field of experimental psychology. Pavlov noticed that dogs would salivate when they saw food. He then began to ring a bell each time he presented the food to the dogs. After a while, the dogs began to salivate merely at the sound of the bell. This experiment demonstrated the principle of “classical conditioning.”

10, Piaget’s Stages of Development (Piaget, 1958) Jean Piaget proposed a theory of cognitive development in children that consists of four distinct stages: the sensorimotor stage (birth to 2 years), where children learn about the world through their senses and motor activities, through to the the formal operational stage (12 years and beyond), where abstract reasoning and hypothetical thinking develop. Piaget’s theory is an example of experimental psychology as it was developed through systematic observation and experimentation on children’s problem-solving behaviors .

Types of Research Methodologies in Experimental Psychology 

Researchers utilize several different types of research methodologies since the early days of Wundt (1832-1920).

1. The Experiment

The experiment involves the researcher manipulating the level of one variable, called the Independent Variable (IV), and then observing changes in another variable, called the Dependent Variable (DV).

The researcher is interested in determining if the IV causes changes in the DV. For example, does television violence make children more aggressive?

So, some children in the study, called research participants, will watch a show with TV violence, called the treatment group. Others will watch a show with no TV violence, called the control group.

So, there are two levels of the IV: violence and no violence. Next, children will be observed to see if they act more aggressively. This is the DV.

If TV violence makes children more aggressive, then the children that watched the violent show will me more aggressive than the children that watched the non-violent show.

A key requirement of the experiment is random assignment . Each research participant is assigned to one of the two groups in a way that makes it a completely random process. This means that each group will have a mix of children: different personality types, diverse family backgrounds, and range of intelligence levels.

2. The Longitudinal Study

A longitudinal study involves selecting a sample of participants and then following them for years, or decades, periodically collecting data on the variables of interest.

For example, a researcher might be interested in determining if parenting style affects academic performance of children. Parenting style is called the predictor variable , and academic performance is called the outcome variable .

Researchers will begin by randomly selecting a group of children to be in the study. Then, they will identify the type of parenting practices used when the children are 4 and 5 years old.

A few years later, perhaps when the children are 8 and 9, the researchers will collect data on their grades. This process can be repeated over the next 10 years, including through college.

If parenting style has an effect on academic performance, then the researchers will see a connection between the predictor variable and outcome variable.

Children raised with parenting style X will have higher grades than children raised with parenting style Y.

3. The Case Study

The case study is an in-depth study of one individual. This is a research methodology often used early in the examination of a psychological phenomenon or therapeutic treatment.

For example, in the early days of treating phobias, a clinical psychologist may try teaching one of their patients how to relax every time they see the object that creates so much fear and anxiety, such as a large spider.

The therapist would take very detailed notes on how the teaching process was implemented and the reactions of the patient. When the treatment had been completed, those notes would be written in a scientific form and submitted for publication in a scientific journal for other therapists to learn from.

There are several other types of methodologies available which vary different aspects of the three described above. The researcher will select a methodology that is most appropriate to the phenomenon they want to examine.

They also must take into account various practical considerations such as how much time and resources are needed to complete the study. Conducting research always costs money.

People and equipment are needed to carry-out every study, so researchers often try to obtain funding from their university or a government agency. 

Origins and Key Developments in Experimental Psychology

Wilhelm Maximilian Wundt (1832-1920) is considered one of the fathers of modern psychology. He was a physiologist and philosopher and helped establish psychology as a distinct discipline (Khaleefa, 1999).  

In 1879 he established the world’s first psychology research lab at the University of Leipzig. This is considered a key milestone for establishing psychology as a scientific discipline. In addition to being the first person to use the term “psychologist,” to describe himself, he also founded the discipline’s first scientific journal Philosphische Studien in 1883.

Another notable figure in the development of experimental psychology is Ernest Weber . Trained as a physician, Weber studied sensation and perception and created the first quantitative law in psychology.

The equation denotes how judgments of sensory differences are relative to previous levels of sensation, referred to as the just-noticeable difference (jnd). This is known today as Weber’s Law (Hergenhahn, 2009).    

Gustav Fechner , one of Weber’s students, published the first book on experimental psychology in 1860, titled Elemente der Psychophysik. His worked centered on the measurement of psychophysical facets of sensation and perception, with many of his methods still in use today.    

The first American textbook on experimental psychology was Elements of Physiological Psychology, published in 1887 by George Trumball Ladd .

Ladd also established a psychology lab at Yale University, while Stanley Hall and Charles Sanders continued Wundt’s work at a lab at Johns Hopkins University.

In the late 1800s, Charles Pierce’s contribution to experimental psychology is especially noteworthy because he invented the concept of random assignment (Stigler, 1992; Dehue, 1997).

Go Deeper: 15 Random Assignment Examples

This procedure ensures that each participant has an equal chance of being placed in any of the experimental groups (e.g., treatment or control group). This eliminates the influence of confounding factors related to inherent characteristics of the participants.

Random assignment is a fundamental criterion for a study to be considered a valid experiment.

From there, experimental psychology flourished in the 20th century as a science and transformed into an approach utilized in cognitive psychology, developmental psychology, and social psychology .

Today, the term experimental psychology refers to the study of a wide range of phenomena and involves methodologies not limited to the manipulation of variables.

The Scientific Process and Experimental Psychology

The one thing that makes psychology a science and distinguishes it from its roots in philosophy is the reliance upon the scientific process to answer questions. This makes psychology a science was the main goal of its earliest founders such as Wilhelm Wundt.

There are numerous steps in the scientific process, outlined in the graphic below.

1. Observation

First, the scientist observes an interesting phenomenon that sparks a question. For example, are the memories of eyewitnesses really reliable, or are they subject to bias or unintentional manipulation?

2. Hypothesize

Next, this question is converted into a testable hypothesis. For instance: the words used to question a witness can influence what they think they remember.

3. Devise a Study

Then the researcher(s) select a methodology that will allow them to test that hypothesis. In this case, the researchers choose the experiment, which will involve randomly assigning some participants to different conditions.

In one condition, participants are asked a question that implies a certain memory (treatment group), while other participants are asked a question which is phrased neutrally and does not imply a certain memory (control group).

The researchers then write a proposal that describes in detail the procedures they want to use, how participants will be selected, and the safeguards they will employ to ensure the rights of the participants.

That proposal is submitted to an Institutional Review Board (IRB). The IRB is comprised of a panel of researchers, community representatives, and other professionals that are responsible for reviewing all studies involving human participants.

4. Conduct the Study

If the IRB accepts the proposal, then the researchers may begin collecting data. After the data has been collected, it is analyzed using a software program such as SPSS.

Those analyses will either support or reject the hypothesis. That is, either the participants’ memories were affected by the wording of the question, or not.

5. Publish the study

Finally, the researchers write a paper detailing their procedures and results of the statistical analyses. That paper is then submitted to a scientific journal.

The lead editor of that journal will then send copies of the paper to 3-5 experts in that subject. Each of those experts will read the paper and basically try to find as many things wrong with it as possible. Because they are experts, they are very good at this task.

After reading those critiques, most likely, the editor will send the paper back to the researchers and require that they respond to the criticisms, collect more data, or reject the paper outright.

In some cases, the study was so well-done that the criticisms were minimal and the editor accepts the paper. It then gets published in the scientific journal several months later.

That entire process can easily take 2 years, usually more. But, the findings of that study went through a very rigorous process. This means that we can have substantial confidence that the conclusions of the study are valid.

Experimental psychology refers to utilizing a scientific process to investigate psychological phenomenon.

There are a variety of methods employed today. They are used to study a wide range of subjects, including memory, cognitive processes, emotions and the neurophysiological basis of each.

The history of psychology as a science began in the 1800s primarily in Germany. As interest grew, the field expanded to the United States where several influential research labs were established.

As more methodologies were developed, the field of psychology as a science evolved into a prolific scientific discipline that has provided invaluable insights into human behavior.

Bartlett, F. C., & Bartlett, F. C. (1995).  Remembering: A study in experimental and social psychology . Cambridge university press.

Dehue, T. (1997). Deception, efficiency, and random groups: Psychology and the gradual origination of the random group design. Isis , 88 (4), 653-673.

Ebbinghaus, H. (2013). Memory: A contribution to experimental psychology.  Annals of neurosciences ,  20 (4), 155.

Hergenhahn, B. R. (2009). An introduction to the history of psychology. Belmont. CA: Wadsworth Cengage Learning .

Khaleefa, O. (1999). Who is the founder of psychophysics and experimental psychology? American Journal of Islam and Society , 16 (2), 1-26.

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

Pavlov, I.P. (1927). Conditioned reflexes . Dover, New York.

Piaget, J. (1959).  The language and thought of the child  (Vol. 5). Psychology Press.

Piaget, J., Fraisse, P., & Reuchlin, M. (2014). Experimental psychology its scope and method: Volume I (Psychology Revivals): History and method . Psychology Press.

Skinner, B. F. (1956). A case history in scientlfic method. American Psychologist, 11 , 221-233

Stigler, S. M. (1992). A historical view of statistical concepts in psychology and educational research. American Journal of Education , 101 (1), 60-70.

Thorndike, E. L. (1898). Animal intelligence: An experimental study of the associative processes in animals. Psychological Review Monograph Supplement 2 .

Wolpe, J. (1958). Psychotherapy by reciprocal inhibition. Stanford, CA: Stanford University Press.

Appendix: Images reproduced as Text

Definition: Experimental psychology is a branch of psychology that focuses on conducting systematic and controlled experiments to study human behavior and cognition.

Overview: Experimental psychology aims to gather empirical evidence and explore cause-and-effect relationships between variables. Experimental psychologists utilize various research methods, including laboratory experiments, surveys, and observations, to investigate topics such as perception, memory, learning, motivation, and social behavior .

Example: The Pavlov’s Dog experimental psychology experiment used scientific methods to develop a theory about how learning and association occur in animals. The same concepts were subsequently used in the study of humans, wherein psychology-based ideas about learning were developed. Pavlov’s use of the empirical evidence was foundational to the study’s success.

Experimental Psychology Milestones:

1890: William James publishes “The Principles of Psychology”, a foundational text in the field of psychology.

1896: Lightner Witmer opens the first psychological clinic at the University of Pennsylvania, marking the beginning of clinical psychology.

1913: John B. Watson publishes “Psychology as the Behaviorist Views It”, marking the beginning of Behaviorism.

1920: Hermann Rorschach introduces the Rorschach inkblot test.

1938: B.F. Skinner introduces the concept of operant conditioning .

1967: Ulric Neisser publishes “Cognitive Psychology” , marking the beginning of the cognitive revolution.

1980: The third edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-III) is published, introducing a new classification system for mental disorders.

The Scientific Process

• Observe an interesting phenomenon
• Formulate testable hypothesis
• Select methodology and design study
• Submit research proposal to IRB
• Collect and analyzed data; write paper
• Submit paper for critical reviews

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experimental psychology

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• American Psychological Association - Understanding Experimental Psychology

experimental psychology , a method of studying psychological phenomena and processes. The experimental method in psychology attempts to account for the activities of animals (including humans) and the functional organization of mental processes by manipulating variables that may give rise to behaviour; it is primarily concerned with discovering laws that describe manipulable relationships. The term generally connotes all areas of psychology that use the experimental method.

These areas include the study of sensation and perception , learning and memory , motivation , and biological psychology . There are experimental branches in many other areas, however, including child psychology , clinical psychology , educational psychology , and social psychology . Usually the experimental psychologist deals with normal, intact organisms; in biological psychology, however, studies are often conducted with organisms modified by surgery, radiation, drug treatment, or long-standing deprivations of various kinds or with organisms that naturally present organic abnormalities or emotional disorders. See also psychophysics .

Experimental Psychology

Definition:

Experimental psychology is a subfield of psychology that focuses on scientific investigation and research methods to study human behavior and mental processes. It involves conducting controlled experiments to examine hypotheses and gather empirical data.

Subfields of Experimental Psychology:

Sensory processes:.

Sensory processes in experimental psychology involve understanding how humans perceive and process information through their senses, such as vision, hearing, taste, smell, and touch.

Learning and Memory:

This subfield explores how individuals acquire and retain knowledge and skills, including the study of different types of memory, learning strategies, and factors that influence memory processes.

Cognitive Psychology:

Cognitive psychology examines mental processes, including attention, perception, problem-solving, decision-making, language, and thinking. It investigates how individuals process information, solve problems, and make decisions.

Developmental Psychology:

Developmental psychology focuses on the study of human development across the lifespan, from infancy to old age. It investigates how individuals change physically, cognitively, and emotionally as they grow and mature.

Social Psychology:

Social psychology studies how individuals’ thoughts, feelings, and behaviors are influenced by social interactions and social environments. It examines topics such as conformity, persuasion, group dynamics, and intergroup relations.

Personality Psychology:

Personality psychology aims to understand individual differences in behavior, thoughts, and emotions. It investigates various personality traits, their development, and how they influence behavior and well-being.

Psychopathology:

This subfield focuses on the study of mental disorders, their causes, symptoms, and treatments. Psychopathology research is often conducted using experimental methods to examine the effectiveness of therapeutic interventions.

Psychopharmacology:

Psychopharmacology involves studying the effects of drugs on behavior, cognition, and emotions. It examines how different medications impact mental processes and aims to develop effective pharmacological treatments for psychological disorders.

Neuropsychology:

Neuropsychology investigates the relationship between brain function and behavior. It examines how brain damage, genetics, and neurological disorders affect cognitive abilities, emotions, and behavior.

An Introduction to Experimental Psychology: Principles, Applications, and Discoveries

Curious about the inner workings of the human mind? Experimental psychology delves into the complexities of human behavior and cognition through rigorous scientific methods.

In this article, we explore the goals and principles of experimental psychology, its diverse applications in fields such as clinical and educational psychology, and some of the groundbreaking discoveries that have shaped our understanding of human behavior.

Join us on a journey through the fascinating world of experimental psychology.

• Experimental psychology uses an empirical approach to study behavior and mental processes.
• Objectivity, control, and replication are essential principles in experimental psychology.
• This field has applications in clinical, educational, industrial, and forensic settings.
• Some famous discoveries in experimental psychology include classical and operant conditioning, obedience and eyewitness studies, and attachment research.
• 1.1 What Is the Goal of Experimental Psychology?
• 2.1 Empirical Approach
• 2.2 Objectivity
• 2.3 Control
• 2.4 Replication
• 3.1 Clinical Psychology
• 3.2 Educational Psychology
• 3.3 Industrial and Organizational Psychology
• 3.4 Forensic Psychology
• 4.1 Pavlov’s Classical Conditioning
• 4.2 Skinner’s Operant Conditioning
• 4.3 Milgram’s Obedience Study
• 4.4 Loftus and Palmer’s Eyewitness Testimony Study
• 4.5 Bandura’s Bobo Doll Experiment
• 4.6 Harlow’s Attachment Study
• 5.1 What is experimental psychology?
• 5.2 What are the main principles of experimental psychology?
• 5.3 How is experimental psychology applied in real life?
• 5.4 What are some famous discoveries in experimental psychology?
• 5.5 What are some common research methods used in experimental psychology?
• 5.6 How can I get involved in experimental psychology?

What Is Experimental Psychology?

Experimental psychology is a branch of psychology that focuses on understanding human behavior, perception, cognition, and emotions through systematic research and studies.

One of the key goals of experimental psychology is to apply scientific methods to investigate various phenomena, such as memory, attention, decision-making, and motivation. Researchers in this field often employ controlled experiments to test hypotheses and gather empirical evidence. By manipulating variables in carefully designed studies, experimental psychologists aim to elucidate the underlying mechanisms that drive human behavior. Through these investigations, they can also uncover patterns and principles that contribute to the development of psychological theories and models.

What Is the Goal of Experimental Psychology?

The primary goal of experimental psychology is to uncover the underlying mechanisms that govern human behavior, perception, cognition, and emotions through controlled scientific studies and rigorous experimentation.

By conducting carefully designed experiments and observing human responses in controlled settings, experimental psychologists aim to establish causal relationships between variables and outcomes, shedding light on the intricate workings of the human mind and behavior.

Scientific rigor is paramount in this field, ensuring that findings are reliable and valid, contributing to the cumulative knowledge base of psychology.

Through the systematic manipulation of independent variables and measurement of dependent variables, researchers in experimental psychology strive to elucidate the complexities of human cognition, emotion, and behavior.

What Are the Principles of Experimental Psychology?

The principles of experimental psychology are founded on key tenets such as an empirical approach , objectivity, control, and replication, which form the basis for conducting rigorous scientific investigations into human behavior, perception, cognition, and emotions.

Experimental psychology’s reliance on an empirical approach ensures that research conclusions are based on observable evidence rather than subjective opinions. This emphasis on objectivity minimizes bias and strengthens the reliability of study outcomes. The control over variables allows researchers to isolate specific factors influencing behavior, aiding in the establishment of causal relationships. By replicating findings, psychologists verify the robustness and validity of their results, contributing to the advancement of knowledge within the field.

Empirical Approach

The empirical approach in experimental psychology emphasizes the reliance on direct observation, data collection, and experimentation to investigate and understand human behavior, perception, cognition, and emotions in a systematic and scientific manner.

This approach is fundamental in gathering objective and quantifiable data that can be analyzed to draw meaningful conclusions about various aspects of human psychology. Utilizing controlled experiments, researchers can manipulate variables to observe the cause and effect relationships, which provides valuable insights into the underlying mechanisms of behavior. Through meticulous experimental designs, such as within-subject and between-subject studies, researchers can compare different conditions and assess the impact of specific factors on human responses. Employing rigorous data collection techniques, including surveys, interviews, and physiological measurements, enables researchers to gather comprehensive data sets for in-depth analysis.

Objectivity

Objectivity is a crucial principle in experimental psychology, ensuring that researchers maintain a neutral and unbiased perspective when conducting studies, analyzing data, and interpreting results related to human behavior, perception, cognition, and emotions.

It is essential for researchers to approach their experiments with a mindset free from personal biases, preconceptions, or preferences, as these can cloud judgment and impact the validity of their findings. By adhering to the principle of objectivity, psychologists strive to minimize the influence of their own beliefs, emotions, or expectations on the research process.

Impartiality in data collection and analysis is fundamental for drawing accurate and reliable conclusions. Researchers must gather information systematically, without favoring certain outcomes, and interpret results objectively to avoid skewing the findings in any particular direction.

Control is a fundamental principle in experimental psychology, enabling researchers to manipulate variables, establish cause-and-effect relationships, and minimize extraneous influences that could impact the study of human behavior, perception, cognition, and emotions.

This principle of control plays a crucial role in the meticulous design of experiments. By carefully designing studies with controlled variables, researchers can precisely isolate the effects of the variables under investigation.

Through skilled manipulation of these variables, within a controlled setting, researchers can ascertain the causal relationships between them and the resulting outcomes observed.

This meticulous process not only allows for a deeper understanding of human behavior, perception, cognition, and emotions but also contributes significantly to the advancement of knowledge in the field of experimental psychology.

Replication

Replication is a critical principle in experimental psychology that emphasizes the need to reproduce research findings consistently through repeated studies, enhancing the reliability and validity of conclusions related to human behavior, perception, cognition, and emotions.

By replicating studies, researchers can verify the accuracy and generalizability of their results, ensuring that the observed effects are not merely due to chance or specific experimental conditions.

Replication also allows for the identification of potential errors or biases that may have influenced initial findings. The process of replication contributes to the cumulative nature of scientific knowledge, building a solid foundation of evidence that can withstand scrutiny and contribute to the advancement of the field.

What Are the Applications of Experimental Psychology?

Experimental psychology finds diverse applications in various subfields such as clinical psychology, educational psychology, industrial and organizational psychology, and forensic psychology, where insights into human behavior, perception, cognition, and emotions are utilized to address specific challenges and phenomena.

For instance, in clinical psychology, experimental findings help in understanding the mechanisms underlying mental disorders and developing effective therapeutic interventions. Educational psychology benefits from research on learning processes and memory retention to enhance teaching methods and curriculum designs.

In the industrial and organizational psychology domain, experimental studies play a crucial role in optimizing workplace environments, employee motivation, and leadership strategies. Forensic psychology relies on experimental investigations to analyze witness testimonies, jury decision-making, and offender behavior for legal proceedings.

Clinical Psychology

Clinical psychology utilizes insights from experimental psychology to understand and treat mental health disorders, behavioral issues, and emotional disturbances by applying evidence-based interventions and therapies rooted in scientific research on human behavior, perception, cognition, and emotions.

By integrating the findings of experimental psychology into clinical practice, psychologists are able to enhance their understanding of the underlying mechanisms that drive various psychological conditions. For instance, research on memory, learning, and decision-making processes has greatly contributed to the development of effective therapeutic techniques for individuals dealing with trauma or addiction.

This interdisciplinary approach allows clinicians to tailor their treatment strategies to address the specific needs of each patient, leading to more personalized and successful outcomes in therapy. Experimental psychology informs the assessment methods used in diagnosing disorders and monitoring treatment progress, enabling psychologists to make data-driven decisions to optimize patient care.

Educational Psychology

Educational psychology integrates experimental research on learning , memory , motivation , and cognition to enhance teaching practices, curriculum design, and student outcomes, leveraging scientific insights into human behavior and cognition to optimize educational strategies and interventions.

Experimental psychology plays a pivotal role within educational settings by providing valuable empirical evidence that informs and shapes the methodologies and approaches used in teaching. Through rigorous experimentation and analysis, researchers in this field uncover patterns and trends in how individuals learn, process information, and engage with educational content.

By applying the findings from experimental psychology studies, educators can tailor their instructional techniques, adjust curricula, and enhance classroom environments to better suit the diverse learning needs of students. This evidence-based approach ensures that teaching practices are rooted in science and adapted to align with the cognitive processes and needs of learners.

Industrial and Organizational Psychology

Industrial and organizational psychology employs experimental methods to investigate workplace behaviors, organizational dynamics, leadership styles, and employee motivation, utilizing scientific insights into human behavior, cognition, and emotions to enhance productivity, job satisfaction, and organizational effectiveness.

Through the lens of experimental psychology, organizations can gain valuable insights into how individuals interact within teams, respond to stressors, and make decisions in the workplace. By conducting controlled experiments and observational studies, researchers can uncover underlying psychological mechanisms influencing performance, communication patterns, and job satisfaction. These findings not only help in designing effective training programs and assessment tools but also provide a foundation for developing strategies to create a positive work environment, reduce conflicts, and foster leadership development.

Forensic Psychology

Forensic psychology relies on experimental research to analyze criminal behavior, witness testimony, investigative techniques, and judicial decision-making, using scientific insights into human behavior, cognition, and emotions to inform legal proceedings, criminal investigations, and justice systems.

Experimental psychology plays a vital role in the field of forensic psychology by providing a scientific approach to understanding the complexities of human behavior in legal contexts. Through controlled experiments and research studies, psychologists can delve into the underlying factors that influence criminal conduct and witness testimonies.

The application of experimental findings in forensic contexts aids in assessing the credibility of witnesses, identifying patterns of deception, and enhancing investigative strategies to uncover crucial evidence for legal proceedings. By integrating empirical data and psychological theories, forensic psychologists can contribute valuable insights to the judicial system and law enforcement agencies.

What Are Some Famous Discoveries in Experimental Psychology?

Experimental psychology has witnessed several landmark discoveries that have shaped our understanding of human behavior, perception, cognition, and emotions, including Pavlov’s Classical Conditioning, Skinner’s Operant Conditioning, Milgram’s Obedience Study, Loftus and Palmer’s Eyewitness Testimony Study, Bandura’s Bobo Doll Experiment, and Harlow’s Attachment Study.

These experiments have significantly influenced the field by providing key insights into human learning, social behavior, memory, and attachment. For instance, Pavlov’s Classical Conditioning demonstrated how associations can be formed between stimuli and responses, laying the foundation for understanding various learned behaviors. Skinner’s Operant Conditioning further elucidated the role of consequences in shaping behavior, emphasizing the importance of reinforcement and punishment in learning processes.

Milgram’s Obedience Study shed light on the power of authority in influencing individuals’ actions, revealing the disturbing extent to which people may comply with unethical commands. Loftus and Palmer’s Eyewitness Testimony Study challenged the reliability of memory and highlighted how external factors can distort recollections of events.

Bandura’s Bobo Doll Experiment pioneered the concept of observational learning, showing how individuals can acquire new behaviors through modeling others, impacting our understanding of social learning processes. Harlow’s Attachment Study revolutionized our understanding of attachment in primates by demonstrating the importance of social and emotional bonds in development.

Pavlov’s Classical Conditioning

Pavlov’s Classical Conditioning experiment demonstrated how associative learning occurs in response to stimuli, establishing a foundational principle in psychology that explains how behaviors can be modified through conditioning processes involving stimulus-response associations.

The groundbreaking study conducted by Ivan Pavlov involved ringing a bell before presenting food to dogs, initially causing them to salivate only at the sight and smell of food. Through repeated pairings of the bell and food, the dogs started associating the bell with the upcoming meal, eventually eliciting a salivary response even without food presence.

• The findings of Pavlov’s experiment showcased the phenomenon of conditioned response where previously neutral stimuli come to evoke specific behaviors due to repeated pairings with meaningful stimuli.

This essential insight into behavioral conditioning has led to a profound understanding of how learning and modification of behaviors can be achieved by manipulating environmental cues and responses.

Skinner’s Operant Conditioning

Skinner’s Operant Conditioning research elucidated how behaviors are influenced by consequences such as rewards and punishments, providing insights into operant behaviors and reinforcement principles that shape learning and behavior modification.

Skinner’s experiments involved studying how organisms learn through the consequences of their actions. He identified two main types of consequences: reinforcement and punishment. Reinforcement, which includes positive reinforcement where a behavior is strengthened by a rewarding stimulus, and negative reinforcement, where a behavior is strengthened by the removal of an aversive stimulus, plays a crucial role in shaping behavior. On the other hand, punishment involves the application of an aversive stimulus to decrease the likelihood of a behavior recurring. These concepts not only help understand how behaviors are learned but also provide effective tools for behavior modification in various fields such as education, psychology, and therapy.

Milgram’s Obedience Study

Milgram’s Obedience Study investigated the extent to which individuals comply with authority figures, revealing the powerful influence of situational factors on human behavior, obedience, and ethical considerations in social psychology.

The experimental setup of Milgram’s Obedience Study involved a simulated scenario where participants, who believed they were administering electric shocks to another person, were instructed by an authority figure to continue escalating the voltage despite hearing cries of pain. This controlled environment aimed to examine how ordinary individuals respond to perceived authority, shedding light on the psychological mechanisms underlying obedience.

The findings of the study were startling, indicating that a significant proportion of participants were willing to administer potentially harmful shocks to the ‘learner’ simply due to the influence of the authoritative instruction. This highlighted the profound impact of situational factors, such as the presence of an authority figure, on shaping behavior even against one’s moral compass.

Loftus and Palmer’s Eyewitness Testimony Study

Loftus and Palmer’s Eyewitness Testimony Study demonstrated how memory reconstruction can be influenced by leading questions, highlighting the malleability of memory and the impact of suggestion on eyewitness accounts in legal contexts.

Elizabeth Loftus and John Palmer conducted a series of experiments where participants were shown a video of a car accident. They were then asked questions, with one group being asked how fast the cars smashed into each other while another was asked how fast they contacted each other. The study found that the language used significantly altered participants’ estimates of the speed of the cars, showcasing the power of wording on memory retrieval and perception.

Bandura’s Bobo Doll Experiment

Bandura’s Bobo Doll Experiment illustrated the concept of observational learning, showing how individuals acquire new behaviors by observing and imitating others, thereby contributing to our understanding of social learning processes and behavior modeling.

The experiment, conducted in 1961 by psychologist Albert Bandura, involved children observing an adult model behaving aggressively towards a Bobo doll. The children were then placed in a room with toys, including the Bobo doll, and were observed to see if they would imitate the aggressive behaviors. Results showed that children who had witnessed the adult’s aggressive actions were more likely to replicate them, highlighting the power of observational learning in shaping behavior.

Harlow’s Attachment Study

Harlow’s Attachment Study with infant rhesus monkeys revealed the critical role of contact comfort in attachment formation, challenging prevailing beliefs about attachment theory and highlighting the significance of social bonding and emotional connections in developmental psychology.

The groundbreaking experiment conducted by Harlow involved separating infant monkeys from their biological mothers and providing them with two surrogate mothers – one made of wire with a feeding bottle and the other covered in soft cloth without a feeding mechanism. Most surprisingly, the baby monkeys chose to spend the majority of their time clinging to the cloth mother , emphasizing the importance of comfort and security in attachment relationships. This study reshaped the understanding of attachment dynamics by demonstrating that emotional closeness and comfort are fundamental for healthy social and emotional development, rather than just physical nourishment.

Frequently Asked Questions

What is experimental psychology.

Experimental psychology is a branch of psychology that focuses on using scientific methods to study human behavior and mental processes.

What are the main principles of experimental psychology?

The main principles of experimental psychology include objectivity, control, and replicability. Objectivity involves using unbiased methods to collect and analyze data. Control refers to the ability to manipulate variables and isolate their effects. Replicability involves being able to repeat an experiment and obtain similar results.

How is experimental psychology applied in real life?

Experimental psychology has various applications, such as understanding and treating mental disorders, improving education and learning, and informing public policies and practices. It is also used in market research, product development, and advertising.

What are some famous discoveries in experimental psychology?

Some famous discoveries in experimental psychology include Ivan Pavlov’s classical conditioning, B.F. Skinner’s operant conditioning, Stanley Milgram’s obedience experiments, and Philip Zimbardo’s Stanford prison experiment.

What are some common research methods used in experimental psychology?

Experimental psychologists use a variety of research methods, such as laboratory experiments, field experiments, surveys, and observational studies. These methods allow them to systematically test hypotheses and gather data on human behavior and mental processes.

How can I get involved in experimental psychology?

If you are interested in experimental psychology, you can pursue a degree in psychology and focus on experimental methods. You can also participate in research studies or volunteer at a psychology research lab. Additionally, you can stay updated on current research and attend conferences or workshops in the field.

Gabriel Silva is a cultural psychologist interested in how cultural contexts influence individual psychology and vice versa. His fieldwork spans multiple continents, studying the diversity of human experience through the lens of psychology. Gabriel’s writings reflect his journey, offering readers a global perspective on the ways culture shapes our identity, values, and interactions with the world.

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B.A. in Psychology

What Is Experimental Psychology?

The science of psychology spans several fields. There are dozens of disciplines in psychology, including abnormal psychology, cognitive psychology and social psychology.

One way to view these fields is to separate them into two types: applied vs. experimental psychology. These groups describe virtually any type of work in psychology.

The following sections explore what experimental psychology is and some examples of what it covers.

Experimental psychology seeks to explore and better understand behavior through empirical research methods. This work allows findings to be employed in real-world applications (applied psychology) across fields such as clinical psychology, educational psychology, forensic psychology, sports psychology, and social psychology. Experimental psychology is able to shed light on people’s personalities and life experiences by examining what the way people behave and how behavior is shaped throughout life, along with other theoretical questions. The field looks at a wide range of behavioral topics including sensation, perception, attention, memory, cognition, and emotion, according to the  American Psychological Association  (APA).

Research is the focus of experimental psychology. Using scientific methods to collect data and perform research, experimental psychology focuses on certain questions, and, one study at a time, reveals information that contributes to larger findings or a conclusion. Due to the breadth and depth of certain areas of study, researchers can spend their entire careers looking at a complex research question.

Experimental Psychology in Action

The APA  writes about  one experimental psychologist, Robert McCann, who is now retired after 19 years working at NASA. During his time at NASA, his work focused on the user experience — on land and in space — where he applied his expertise to cockpit system displays, navigation systems, and safety displays used by astronauts in NASA spacecraft. McCann’s knowledge of human information processing allowed him to help NASA design shuttle displays that can increase the safety of shuttle missions. He looked at human limitations of attention and display processing to gauge what people can reliably see and correctly interpret on an instrument panel. McCann played a key role in helping determining the features of cockpit displays without overloading the pilot or taxing their attention span.

“One of the purposes of the display was to alert the astronauts to the presence of a failure that interrupted power in a specific region,” McCann said, “The most obvious way to depict this interruption was to simply remove (or dim) the white line(s) connecting the affected components. Basic research on visual attention has shown that humans do not notice the removal of a display feature very easily when the display is highly cluttered. We are much better at noticing a feature or object that is suddenly added to a display.” McCann utilized his knowledge in experimental psychology to research and develop this very important development for NASA. 

Valve Corporation

Another experimental psychologist, Mike Ambinder, uses his expertise to help design video games. He is a senior experimental psychologist at Valve Corporation, a video game developer and developer of the software distribution platform Steam. Ambinder told  Orlando Weekly  that his career working on gaming hits such as Portal 2 and Left 4 Dead “epitomizes the intersection between scientific innovation and electronic entertainment.” His career started when he gave a presentation to Valve on applying psychology to game design; this occurred while he was finishing his PhD in experimental design. “I’m very lucky to have landed at a company where freedom and autonomy and analytical decision-making are prized,” he said. “I realized how fortunate I was to work for a company that would encourage someone with a background in psychology to see what they could contribute in a field where they had no prior experience.” 

Ambinder spends his time on data analysis, hardware research, play-testing methodologies, and on any aspect of games where knowledge of human behavior could be useful. Ambinder described Valve’s process for refining a product as straightforward. “We come up with a game design (our hypothesis), and we place it in front of people external to the company (our play-test or experiment). We gather their feedback, and then iterate and improve the design (refining the theory). It’s essentially the scientific method applied to game design, and the end result is the consequence of many hours of applying this process.” To gather play-test data, Ambinder is engaged in the newer field of biofeedback technology, which can quantify gamers’ enjoyment. His research looks at unobtrusive measurements of facial expressions that can achieve such goals. Ambinder is also examining eye-tracking as a next-generation input method.

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Experimental Psychology Studies Humans and Animals

Understanding Experimental Psychology

Our personalities, and to some degree our life experiences, are defined by the way we behave. But what influences the way we behave in the first place? How does our behavior shape our experiences throughout our lives? 

Experimental psychologists are interested in exploring theoretical questions, often by creating a hypothesis and then setting out to prove or disprove it through experimentation. They study a wide range of behavioral topics among humans and animals, including sensation, perception, attention, memory, cognition and emotion.

Experimental Psychology Applied

Experimental psychologists use scientific methods to collect data and perform research. Often, their work builds, one study at a time, to a larger finding or conclusion. Some researchers have devoted their entire career to answering one complex research question. 

These psychologists work in a variety of settings, including universities, research centers, government agencies and private businesses. The focus of their research is as varied as the settings in which they work. Often, personal interest and educational background will influence the research questions they choose to explore. 

In a sense, all psychologists can be considered experimental psychologists since research is the foundation of the discipline, and many psychologists split their professional focus among research, patient care, teaching or program administration. Experimental psychologists, however, often devote their full attention to research — its design, execution, analysis and dissemination. 

Those focusing their careers specifically on experimental psychology contribute work across subfields . For example, they use scientific research to provide insights that improve teaching and learning, create safer workplaces and transportation systems, improve substance abuse treatment programs and promote healthy child development.

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What is Experimental Psychology?

Bryn Farnsworth

Table of Contents

The mind is a complicated place. Fortunately, the scientific method is perfectly equipped to deal with complexity. If we put these two things together we have the field of experimental psychology, broadly defined as the scientific study of the mind. The word “experimental” in this context means that tests are administered to participants, outcomes are measured, and comparisons are made.

More formally, this means that a group of participants are exposed to a stimulus (or stimuli), and their behavior in response is recorded. This behavior is compared to some kind of control condition, which could be either a neutral stimulus, the absence of a stimulus, or against a control group (who maybe do nothing at all).

Experimental psychology is concerned with testing theories of human thoughts, feelings, actions, and beyond – any aspect of being human that involves the mind. This is a broad category that features many branches within it (e.g. behavioral psychology , cognitive psychology). Below, we will go through a brief history of experimental psychology, the aspects that characterize it, and outline research that has gone on to shape this field.

A Brief History of Experimental Psychology

As with anything, and perhaps particularly with scientific ideas, it’s difficult to pinpoint the exact moment in which a thought or approach was conceived. One of the best candidates with which to credit the emergence of experimental psychology with is Gustav Fechner who came to prominence in the 1830’s. After completing his Ph.D in biology at the University of Leipzig [1], and continuing his work as a professor, he made a significant breakthrough in the conception of mental states.

Scientists later wrote about Fechner’s breakthrough for understanding perception: “An increase in the intensity of a stimulus, Fechner argued, does not produce a one-to-one increase in the intensity of the sensation … For example, adding the sound of one bell to that of an already ringing bell produces a greater increase in sensation than adding one bell to 10 others already ringing. Therefore, the effects of stimulus intensities are not absolute but are relative to the amount of sensation that already exists.” [2]

This ultimately meant that mental perception is responsive to the material world – the mind doesn’t passively respond to a stimulus (if that was the case, there would be a linear relationship between the intensity of a stimulus and the actual perception of it), but is instead dynamically responsive to it. This conception ultimately shapes much of experimental psychology, and the grounding theory: that the response of the brain to the environment can be quantified .

Fechner went on to research within this area for many subsequent years, testing new ideas regarding human perception. Meanwhile, another German scientist working in Heidelberg to the West, began his work on the problem of multitasking, and created the next paradigm shift for experimental psychology. The scientist was Wilhem Wundt, who had followed the work of Gustav Fechner.

Wilhem Wundt is often credited with being “the father of experimental psychology” and is the founding point for many aspects of it. He began the first experimental psychology lab, scientific journal, and ultimately formalized the approach as a science. Wundt set in stone what Fechner had put on paper.

The next scientist to advance the field of experimental psychology was influenced directly by reading Fechner’s book “ Elements of Psychophysics ”. Hermann Ebbinghaus, once again a German scientist, carried out the first properly formalized research into memory and forgetting, by using long lists of (mostly) nonsense syllables (such as: “VAW”, “TEL”, “BOC”) and recording how long it took for people to forget them.

Experiments using this list, concerning learning and memory, would take up much of Ebbinghaus’ career, and help cement experimental psychology as a science. There are many other scientists’ whose contributions helped pave the way for the direction, approach, and success of experimental psychology (Hermann von Helmholtz, Ernst Weber, and Mary Whiton Calkins, to name just a few) – all played a part in creating the field as we know it today. The work that they did defined the field, providing it with characteristics that we’ll now go through below.

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What Defines Experimental Psychology?

Defining any scientific field is in itself no exact science – there are inevitably aspects that will be missed. However, experimental psychology features at least three central components that define it: empiricism, falsifiability, and determinism . These features are central to experimental psychology but also many other fields within science.

Empiricism refers to the collection of data that can support or refute a theory. In opposition to purely theoretical reasoning, empiricism is concerned with observations that can be tested. It is based on the idea that all knowledge stems from observations that can be perceived, and data surrounding them can be collected to form experiments.

Falsifiability is a foundational aspect of all contemporary scientific work. Karl Popper , a 20th century philosopher, formalized this concept – that for any theory to be scientific there must be a way to falsify it. Otherwise, ludicrous, but unprovable claims could be made with equal weight as the most rigorously tested theories.

For example, the Theory of Relativity is scientific, for example, because it is possible that evidence could emerge to disprove it. This means that it can be tested. An example of an unfalsifiable argument is that the earth is younger than it appears, but that it was created to appear older than it is – any evidence against this is dismissed within the argument itself, rendering it impossible to falsify, and therefore untestable.

Determinism refers to the notion that any event has a cause before it. Applied to mental states, this means that the brain responds to stimuli, and that these responses can ultimately be predicted, given the correct data.

These aspects of experimental psychology run throughout the research carried out within this field. There are thousands of articles featuring research that have been carried out within this vein – below we will go through just a few of the most influential and well-cited studies that have shaped this field, and look to the future of experimental psychology.

Classic Studies in Experimental Psychology

Little albert.

One of the most notorious studies within experimental psychology was also one of the foundational pieces of research for behaviorism. Popularly known as the study of “Little Albert”, this experiment, carried out in 1920, focused on whether a baby could be made to fear a stimulus through conditioning (conditioning refers to the association of a response to a stimulus) [3].

The psychologist, John B. Watson , devised an experiment in which a baby was exposed to an unconditioned stimulus (in this case, a white rat) at the same time as a fear-inducing stimulus (the loud, sudden sound of a hammer hitting a metal bar). The repetition of this loud noise paired with the appearance of the white rat eventually led to the white rat becoming a conditioned stimulus – inducing the fear response even without the sound of the hammer.

While the study was clearly problematic, and wouldn’t (and shouldn’t!) clear any ethical boards today, it was hugely influential for its time, showing how human emotional responses can be shaped intentionally by conditioning – a feat only carried out with animals prior to this [4].

Watson, later referred to by a previous professor of his as a person “who thought too highly of himself and was more interested in his own ideas than in people” [5], was later revered and reviled in equal measure [2]. While his approach has since been rightly questioned, the study was a breakthrough for the conception of human behavior .

Asch’s Conformity Experiment

Three decades following Watson’s infamous experiment, beliefs were studied rather than behavior. Research carried out by Solomon Asch in 1951 showed how the influence of group pressure could make people say what they didn’t believe.

The goal was to examine how social pressures “induce individuals to resist or to yield to group pressures when the latter are perceived to be contrary to fact” [6]. Participant’s were introduced to a group of seven people in which, unbeknownst to them, all other individuals were actors hired by Asch. The task was introduced as a perceptual test, in which the length of lines was to be compared.

Sets of lines were shown to the group of participants – three on one card, one on another (as in the image above). The apparent task was to compare the three lines and say which was most like the single line in length. The answers were plainly obvious, and in one-on-one testing, participants got a correct answer over 99% of the time. Yet in this group setting, in which each actor, one after the other, incorrectly said an incorrect line out loud, the answers of the participants would change.

On average, around 38% of the answers the participants gave were incorrect – a huge jump from the less than 1% reported in non-group settings. The study was hugely influential for showing how our actions can be impacted by the environment we are placed in, particularly when it comes to social factors.

The Invisible Gorilla

If you don’t know this research from the title already, then it’s best experienced by watching the video below, and counting the number of ball passes.

The research of course has little to do with throwing a ball around, but more to do with the likelihood of not seeing the person in a gorilla costume who appears in the middle of the screen for eight seconds. The research, carried out in 1999, investigated how our attentional resources can impact how we perceive the world [7]. The term “ inattentional blindness ” refers to the effective blindness of our perceptions when our attention is engaged in another task.

The study tested how attentional processing is distributed, suggesting that objects that are more relevant to the task are more likely to be seen than objects which simply have close spatial proximity (very roughly – something expected is more likely to be seen even if it’s further away, whereas something unexpected is less likely to be seen even if it’s close).

The research not only showed the effect of our perceptions on our experience, but also has real-world implications. A replication of this study was done using eye tracking to record the visual search of radiologists who were instructed to look for nodules on one of several X-rays of lungs [8]. As the researchers state “A gorilla, 48 times the size of the average nodule, was inserted in the last case that was presented . Eighty-three percent of the radiologists did not see the gorilla.”

The original study, and research that followed since, has been crucial for showing how our expectations about the environment can shape our perceptions. Modern research has built upon each of the ideas and studies that have been carried out across almost 200 years.

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The Future of Experimental Psychology

The majority of this article has been concerned with what experimental psychology is, where it comes from, and what it has achieved so far. An inevitable follow-up question to this is – where is it going?

While predictions are difficult to make, there are at least indications. The best place to look is to experts in the field. Schultz and Schultz refer to modern psychology “as the science of behavior and mental processes instead of only behavior, a science seeking to explain overt behavior and its relationship to mental processes.” [2].

The Association for Psychological Science (APS) asked for forecasts from several prominent psychology researchers ( original article available here ), and received some of the following responses.

Lauri Nummenmaa (Assistant professor, Aalto University, Finland) predicts a similar path to Schultz and Schultz, stating that “a major aim of the future psychological science would involve re-establishing the link between the brain and behavior”. While Modupe Akinola (Assistant professor, Columbia Business School) hopes “that advancements in technology will allow for more unobtrusive ways of measuring bodily responses”.

Kristen Lindquist (Assistant professor of psychology, University of North Carolina School of Medicine) centers in on emotional responses, saying that “We are just beginning to understand how a person’s expectations, knowledge, and prior experiences shape his or her emotions. Emotions play a role in every moment of waking life from decisions to memories to feelings, so understanding emotions will help us to understand the mind more generally.”

Tal Yarkoni (Director, Psychoinformatics Lab, University of Texas at Austin) provides a forthright assessment of what the future of experimental psychology has in store: “psychological scientists will have better data, better tools, and more reliable methods of aggregation and evaluation”.

Whatever the future of experimental psychology looks like, we at iMotions aim to keep providing all the tools needed to carry out rigorous experimental psychology research.

I hope you’ve enjoyed reading this introduction to experimental psychology. If you’d like to get an even closer look at the background and research within this field, then download our free guide to human behavior below.

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[1] Shiraev, E. (2015). A history of psychology . Thousand Oaks, CA: SAGE Publications.

[2] Schultz, D. P., & Schultz, S. E. (2011). A History of Modern Psychology . Cengage, Canada.

[3] Watson, J.B.; Rayner, R. (1920). “Conditioned emotional reactions”. Journal of Experimental Psychology . 3 (1): 1–14. doi:10.1037/h0069608.

[4] Pavlov, I. P. (1928). Lectures on conditioned reflexes . (Translated by W.H. Gantt) London: Allen and Unwin.

[5] Brewer, C. L. (1991). Perspectives on John B. Watson . In G. A. Kimble, M. Wertheimer, & C. White (Eds.), Portraits of pioneers in psychology (pp. 171–186). Washington, DC: American Psychological Association.

[6] Asch, S.E. (1951). Effects of group pressure on the modification and distortion of judgments . In H. Guetzkow (Ed.), Groups, leadership and men(pp. 177–190). Pittsburgh, PA:Carnegie Press.

[7] Simons, D. and Chabris, C. (1999). Gorillas in our midst: sustained inattentional blindness for dynamic events. Perception , 28(9), pp.1059-1074.

[8] Drew, T., Võ, M. L-H., Wolfe, J. M. (2013). The invisible gorilla strikes again: sustained inattentional blindness in expert observers. Psychological Science, 24 (9):1848–1853. doi: 10.1177/0956797613479386.

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What is Experimental Psychology?

Experimental psychology is an interesting subdiscipline of psychology.

On the one hand, it refers to an approach to studying human behavior – the standardized methods and techniques used to collect and analyze data.  On the other hand, experimental psychology is a unique branch, an applied field of psychology that explores theoretical questions about human behavior.

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So, while virtually all psychologists can engage in experimental psychology in one form or another, there are also professionals who spend their entire careers conducting applied experimental research in the field of psychology. This is what deems professionals in this field experimental psychologists.

In this guide, we’ll explore how experimental psychology developed and review some of the methods that are used in conducting studies of behavior. We’ll also discuss types of experiments, survey a few types of psychological experiments, and go over career-related information for experimental psychologists as well.

Let’s get started!

What is The History of Experimental Psychology?

Cognitive psychology is one of the most fascinating fields today. Questions about the nature of human behavior and the connection of the body and mind go back to classic philosophers like Plato and Aristotle. Likewise, the debate over nature vs nurture raged long before experimental psychologists came along in their formal and modern form.

But the centuries of philosophizing about why people behave in the manners in which they behave sparked the interest of scientific researchers to study human behavior in an empirical manner. If the principles of the scientific methods could be used for the study of behavior, perhaps scientists could provide definitive answers to the age-old questions surrounding human behavior.

This is precisely why the experimental psychologist was born.

The first experimental psychology lab in the world was founded in Leipzig, Germany, in 1879 by Wilhelm Wundt. There, Wundt primarily studied feelings and sensations in a structured manner using objective, systematized measures and controls. This mathematical and experimental approach set the precedent for the scientific methods that experimental psychologists and research centers use today. 

For example, Wundt used his background in physiology to design an experiment on sensory processes in which each participant was exposed to the same stimulus, such as the sound of a metronome. Each participant was then asked to provide a report of the sensations they experienced, a process called introspection.

The goal of this experiment was to understand the underlying structure of sensory processes. That is, Wundt was interested in analyzing each of the elements of the human experience involved in sensing the stimulus – the thoughts, senses, feelings, and so forth.

Wundt believed that breaking down the process of a behavior – in this case, sensing a sound – could be done much like a chemist analyzes a chemical compound. If you examine the individual components, you can learn more about the structure underneath the individual components.

While Wundt’s process of introspection didn’t remain a long-lasting approach to studying psychological processes, his insistence on controlling the experimental environment has had a long-term impact on how psychological research is conducted.

The experiments he devised used the same conditions for the experimental subjects – the same stimuli, the same setting, the same lighting, and so forth. By controlling the environment in which research is taking place, Wundt was able to minimize potential confounding variables. Doing so is critically important for any research.

Because Wundt’s laboratory was the first in the world, he is often considered the father of modern psychology. That is, his contributions to the field shifted psychology from a philosophical pursuit to a scientific one.

In the United States, experimental psychology grew out of the efforts of G. Stanley Hall and George Trumbull Ladd .

• Stanley Hall is credited with developing the first experimental psychology lab in the United States, which was located at Johns Hopkins University. Though his career mostly focused on child development and evolutionary psychology, his most significant contribution to psychology was overseeing the early development of the field in the United States. He was the first American to get a doctorate in psychology and he oversaw 11 of the first 14 doctorates to be awarded in the U.S., including those to John Dewey, Lewis Terman, and James McKeen Cattell, each of whom went on to become influential figures in the field in their own rite.

Meanwhile, George Trumbull Ladd, who was a professor of psychology at Yale University, established one of the earliest experimental labs for psychology in the U.S. He is also credited with publishing the first experimental psychology textbook, entitled Elements of Physiological Psychology.

Another important figure in the history of experimental psychology was Wundt’s American contemporary, William James.

His textbook, The Principles of Psychology , is perhaps the most seminal work in the history of psychology. Published in 1890, the book offers insights into the experiments James performed over the course of his career teaching at Harvard. However, the book is not a manual on experimental psychology. In fact, James wasn’t particularly interested in experimental research.

Despite this, James was the first American to teach a psychology course in the United States. He also helped found functionalism, which was one of the earliest schools of thought in psychology. As a result of this, James is often referred to as the father of American psychology.

What is The Methodology of Experimental Psychology?

Almost everyone is familiar with certain experiments, such as a mouse trying to navigate a maze or a primate trying to figure out a puzzle. However, human experiments are much more complex. For example, the experimental psychologist must take into account extraneous variables, environmental conditions, and experimenter bias as potentially skewing the data that’s collected.

Additionally, experimental psychologists must choose an appropriate sample size, correctly define the operations of the experiment, and use sound statistical analyses. Experimental methods must be completely controlled and perfectly executed in order to stand up to peer review, which is one of the foundations of all scientific endeavors.

An experimental method in psychology can take several forms:

• Laboratory experiments , in which researchers carefully control every aspect of the experiment. This includes where, when, and how the experiment will take place, the number and type of participants, standardized procedures, and assignment of participants to the control or experimental group. Lab experiments are easy to replicate and do a good job of controlling for confounding variables. However, lab experiments can produce unnatural behaviors due to the artificial setting and experimenter bias can be an issue.
• Natural experiments , in which researchers conduct their experiments in a real-life setting. This type of research offers no control over the independent variable (and no control over potential confounding variables, either). However, because the research is conducted in a natural environment, it has better ecological validity than lab experiments and it can be used to study behaviors that would be unethical to study in a lab setting, again because the independent variable is naturally occurring. 
• Field experiments , in which research is conducted in a real-life setting, but with the ability to manipulate the independent variable. While this type of research doesn’t allow for control over confounding variables, it offers the advantage of most closely reflecting real behaviors with a lesser likelihood of demand characteristics influencing the final results.

What is The Science of Experimental Psychology?

Experimental psychologists and scientists all believe in the same basic four principles. First, determinism means that all phenomena have some sort of systematic cause. Second, empiricism means that objective observation is the key to interpreting the world around us. Third, parsimony means that scientists prefer a minimalist approach to developing and researching theories. That is, science embraces the principle of Occam’s razor, which means that the theory with the fewest assumptions should be the logical conclusion. Finally, the fourth principle is testability. All theories must be empirically tested with applied falsifiability.

In other words, experimental psychology follows the same maxims of the physical sciences. The purpose is to use the principles of the scientific method to empirically study human behavior to arrive at testable and repeatable conclusions.

To do so, experimental research methods must be reliable and valid. Reliability refers to the consistency of observations, or the repeatability of an observation. Examples of tests of reliability include the split-half method (in which the results from one half of participants is compared to the other half) and the test-retest method (in which measurements are taken of the same group multiple times to see if the results are consistent.

Validity refers to how well a test measures what it’s intended to measure. So, an intelligence test is a valid measure of intelligence. It is not, however, a valid measure of honesty.

Additionally, the science of experimental psychology is rooted in research design. There are many types of designs that experimental psychologists can use, including:

• Within-subjects designs , in which participants in the study are exposed to more than one condition, thereby allowing researchers to compare different data points on the same subject.
• Between-subjects designs , in which participants are exposed to only one condition, which enables researchers to compare data between different subjects.
• One-way designs , in which there is a single independent variable and often just two groups, one of which serves as the control group (which is not exposed to the treatment) and the experimental group (which is exposed to the treatment).
• Factorial designs , which feature two or more independent variables which occur at all levels and in combination with every other independent variable. These experiments are quantified based on their factorial design, such as a 2×3 design. This design has two independent variables, one of which has two levels and the other of which has three.

What Are Some Experiment Examples?

Since experimental psychologists are involved in every branch of psychology, there is an impressive variety of experimental categories.

Social psychology uses field experiments and objective observation to understand collective behavior. For example, researchers might construct a simulated scenario that tests how participants engage in altruistic behavior, such as helping an injured stranger.

On the other hand, cognitive psychologists can use complex equipment and software to analyze the neurological reactions of participants as they watch scary or violent images.

Finally, psychologists studying abnormal behavior, such as phobias or personality disorders, could test participants with these conditions against groups of people that have not been diagnosed with these disorders.

Over the years, there have been many highly influential psychological experiments using various scientific methods. And while their influence has had far-reaching ramifications on our understanding of human behavior, some of these experiments are now viewed as having been unethical. While an experimental psychologist can make a big difference in the world after a successful experimental, their experimental methods do still have to be rational and fair. Psychology research is pointless if people are getting hurt. 

Philip Zimbardo’s Stanford Prison Experiment:

In short, the goal of the experiment was to determine how people conform to social roles. To study this, Zimbardo constructed a makeshift jail in the basement of the psychology building on the Stanford campus. He then recruited 24 male students, each of which were randomly assigned to be a guard or a prisoner.

Prisoners were rounded up and brought to the “prison,” where they were booked and supervised by the group assigned to be guards. Both groups quickly adapted to the roles to which they had ben assigned, with some of the guards engaging in psychological torture of their charges. The experiment ended after just six days because the situation had become so intense and so dangerous.

Despite the questionable ethics of the experiment, it did shed light on conformity and social roles, and how people can very quickly and easily adopt roles they are expected to play, especially when those roles are highly stereotyped

What Are The Careers Options for Experimental Psychology?

According to the American Psychological Association , experimental psychologists seek to answer basic questions about human behavior and mental processes through applied research. These professional perform research to bring light to many topics.

For example, the most popular research topics include memory, emotion, perception and sensation. Typically, experimental psychologists work work in university research centers, but also work for private companies or even the government. Other experimental psychologists may also work in subfields. This may include education (to teach psychology courses), human resources and health care.

Whatever the work setting, you will need a doctorate in psychology to be an experimental psychologist. What’s more, you’ll need to specialize in a particular area of research and pursue post-doctoral studies in that area.

The job outlook for psychology as a whole is about average for the next few years. The Bureau of Labor Statistics (BLS) estimates that all psychology jobs will grow at a rate of three percent through 2029 . The BLS doesn’t provide data specific to experimental psychology, but it’s reasonable to assume that job growth in this field will be on par with the field of psychology as a whole.

In other words, with average job growth for the coming years, competition for experimental psychology jobs will likely be fierce. This is all the more reason to learn about the field, carefully plan your education, and seek out ways in which you can get real-world experience in experimental psychology. The better your combination of education and experience, the more likely you are to stand out in a crowd of other experimental psychology graduates.

Sean Jackson

B.A. Social Studies Education | University of Wyoming

M.S. Counseling | University of Wyoming

B.S. Information Technology | University of Massachusetts

Updated August 2021

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What Careers are in Experimental Psychology?

• The 25 Most Influential Psychological Experiments in History

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What is Experimental Psychology?

The four canons of science, dependent and independent variables, operational definitions.

The operational definition is a way to define abstract ideas to make it observable and measurable. Going back to the study between emotions and memory, which are two very abstract ideas, researchers will need to provide operational definitions to measure the happiness of a person, as well as the strength of his or her memory. As an example, researchers can define happiness through a survey that is filled out by participants to gauge their current state; memory, on the other hand, can be tested by asking participants to recall the order of photos that will be shown to them later on.

Validity and Reliability

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Experimental Group in Psychology Experiments

In a randomized and controlled psychology experiment , the researchers are examining the impact of an experimental condition on a group of participants (does the independent variable 'X' cause a change in the dependent variable 'Y'?). To determine cause and effect, there must be at least two groups to compare, the experimental group and the control group.

The participants who are in the experimental condition are those who receive the treatment or intervention of interest. The data from their outcomes are collected and compared to the data from a group that did not receive the experimental treatment. The control group may have received no treatment at all, or they may have received a placebo treatment or the standard treatment in current practice.

Comparing the experimental group to the control group allows researchers to see how much of an impact the intervention had on the participants.

A Closer Look at Experimental Groups

Imagine that you want to do an experiment to determine if listening to music while working out can lead to greater weight loss. After getting together a group of participants, you randomly assign them to one of three groups. One group listens to upbeat music while working out, one group listens to relaxing music, and the third group listens to no music at all. All of the participants work out for the same amount of time and the same number of days each week.

In this experiment, the group of participants listening to no music while working out is the control group. They serve as a baseline with which to compare the performance of the other two groups. The other two groups in the experiment are the experimental groups.   They each receive some level of the independent variable, which in this case is listening to music while working out.

In this experiment, you find that the participants who listened to upbeat music experienced the greatest weight loss result, largely because those who listened to this type of music exercised with greater intensity than those in the other two groups. By comparing the results from your experimental groups with the results of the control group, you can more clearly see the impact of the independent variable.  

Some Things to Know

When it comes to using experimental groups in a psychology experiment, there are a few important things to know:

• In order to determine the impact of an independent variable, it is important to have at least two different treatment conditions. This usually involves using a control group that receives no treatment against an experimental group that receives the treatment. However, there can also be a number of different experimental groups in the same experiment.
• Care must be taken when assigning participants to groups. So how do researchers determine who is in the control group and who is in the experimental group? In an ideal situation, the researchers would use random assignment to place participants in groups. In random assignment, each individual stands an equal shot at being assigned to either group. Participants might be randomly assigned using methods such as a coin flip or a number draw. By using random assignment, researchers can help ensure that the groups are not unfairly stacked with people who share characteristics that might unfairly skew the results.
• Variables must be well-defined. Before you begin manipulating things in an experiment, you need to have very clear operational definitions in place. These definitions clearly explain what your variables are, including exactly how you are manipulating the independent variable and exactly how you are measuring the outcomes.

A Word From Verywell

Experiments play an important role in the research process and allow psychologists to investigate cause-and-effect relationships between different variables. Having one or more experimental groups allows researchers to vary different levels or types of the experimental variable and then compare the effects of these changes against a control group. The goal of this experimental manipulation is to gain a better understanding of the different factors that may have an impact on how people think, feel, and act.

Byrd-Bredbenner C, Wu F, Spaccarotella K, Quick V, Martin-Biggers J, Zhang Y. Systematic review of control groups in nutrition education intervention research . Int J Behav Nutr Phys Act. 2017;14(1):91. doi:10.1186/s12966-017-0546-3

Steingrimsdottir HS, Arntzen E. On the utility of within-participant research design when working with patients with neurocognitive disorders . Clin Interv Aging. 2015;10:1189-1200. doi:10.2147/CIA.S81868

Oberste M, Hartig P, Bloch W, et al. Control group paradigms in studies investigating acute effects of exercise on cognitive performance—An experiment on expectation-driven placebo effects . Front Hum Neurosci. 2017;11:600. doi:10.3389/fnhum.2017.00600

Kim H. Statistical notes for clinical researchers: Analysis of covariance (ANCOVA) . Restor Dent Endod . 2018;43(4):e43. doi:10.5395/rde.2018.43.e43

Bate S, Karp NA. A common control group — Optimising the experiment design to maximise sensitivity . PLoS ONE. 2014;9(12):e114872. doi:10.1371/journal.pone.0114872

Myers A, Hansen C. Experimental Psychology . 7th Ed. Cengage Learning; 2012.

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

Experimental Method ( AQA A Level Psychology )

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Psychology Content Creator

Experimental Method

Laboratory experiments .

• A lab experiment is a type of research method in which the researcher is able to exert high levels of control over what happens as part of the experimental process
• The researcher controls the environmental factors, such as noise and temperature (possible extraneous variables ) so that the effects of the independent variable (IV) upon the dependent variable (DV) can be clearly observed and measured
• The same number of participants take part in each condition of the IV
• Each participant is given the same instructions (apart from instructions regarding the task as this will differ per condition as per the IV)
• The same task/materials are used as far as is possible given the IV
• Participants are given the same amount of time to complete the task per condition and across conditions if the IV allows it
• All variables are kept the same/constant : only the independent variable changes between conditions
• Keeping all variables constant means the DV can be measured exactly using quantitative data

Evaluation Points 

Field Experiments 

• A field experiment is a research method which takes place in a natural setting, away from the lab
• The researcher has less control over what happens as part of the experimental process
• The researcher controls the environment to some extent but they have to allow the fact that many extraneous variables are included in field experiments
• A confederate of the researcher pretends to collapse on a subway train: the IV is whether the victim appears to be drunk or disabled, the DV is the number of people who go to the victim’s aid
• A researcher implements a ‘Kindness’ programme with half of the Year 5 students in a primary school: the IV is whether the students have followed the ‘Kindness’ programme or not, the DV is the score they achieve on a questionnaire about prosocial behaviour after one month
• Interviews with passengers who witnessed the ‘victim’ collapsing on the train
• Teachers’ observations of behavioural differences in the ‘Kindness’ programme children across the month of the study
• Any qualitative data collected could be used to comment on the quantitative findings and shed light on the actions of the participants

Natural Experiments 

• A natural experiment is a research method which does not manipulate the IV, it uses naturally-occurring phenomena , for example:
• Age e.g. an experiment in which digit-span recall is tested between a group of young people compared to a group of older people
• Gender e.g. the performance of girls is compared to the performance of boys in an experiment testing emotional intelligence
• Circumstances e.g. a group of teachers from one school who have received training in empathy are compared to a group of teachers from another school who have not had this training on a task involving correctly identifying emotional states
• The researcher has less control over what happens as part of the experimental process as they cannot randomly allocate participants to condition (the participants are the conditions e.g. either young/old, trained/untrained)
• Natural experiments collect quantitative data 

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Author: Claire Neeson

Claire has been teaching for 34 years, in the UK and overseas. She has taught GCSE, A-level and IB Psychology which has been a lot of fun and extremely exhausting! Claire is now a freelance Psychology teacher and content creator, producing textbooks, revision notes and (hopefully) exciting and interactive teaching materials for use in the classroom and for exam prep. Her passion (apart from Psychology of course) is roller skating and when she is not working (or watching 'Coronation Street') she can be found busting some impressive moves on her local roller rink.

More From Forbes

What hanumankind’s ‘big dawgs’ teaches us about hidden bias—by a psychologist.

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Have you ever been taken aback by someone’s profession based on their appearance? Here’s how to ... [+] expand your perspective and rethink unconscious biases.

If you’ve been on social media lately, you might have caught wind of Hanumankind’s viral new song “Big Dawgs.” Listeners all over the world love its fantastic beat, hard-hitting lyrics and visually stunning music video. However, many were surprised to learn that Hanumankind is Indian.

Having grown up in Houston before returning to India, his sound naturally reflects U.S. influences. However, the surprise at his origins could hint at unconscious biases lurking within people’s perceptions.

Unconscious or implicit bias refers to attitudes or stereotypes that unconsciously affect our understanding, actions and decisions. These biases are automatic and operate without our awareness, often in ways that contradict our conscious values.

Unconscious biases stem from our natural inclination to categorize information quickly and efficiently. This process involves the brain relying on mental shortcuts developed through experience and societal conditioning. These shortcuts help the brain make rapid decisions, but can lead to biased judgments.

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For instance, unconscious bias can stop you from fully participating in and appreciating new experiences. You might avoid eating at certain restaurants because you believe the food will be bad due to the cuisine or appearance, or in the case of Hanumankind, you might preemptively dismiss his music because you assume it’s not your style, before giving it a real chance.

Here are two ways to avoid the trap of unconscious bias.

1. Expand Your Social Circle

Changing your perception of others is hard when everyone in your social circle mimics your thoughts and beliefs. To avoid living in an echo chamber , you must surround yourself with varying perspectives. Making an effort to interact with a diverse group of people can help broaden your worldview.

Research shows that engaging in “perspective-taking” or considering a situation or experience from another person’s point of view can reduce implicit bias. This practice requires empathy and an open mind, as it challenges individuals to see beyond their own experiences and assumptions. Meeting and listening to new people gives you the chance to do just that.

“I’m a white girl and a lot of my girl friends are black. It’s made me very aware of how real white privilege is,” one reddit user explains, emphasizing the importance of a diverse social circle.

2. Embrace Curiosity

Another way to counteract unconscious bias is to approach situations with curiosity instead of relying on your assumptions. When you encounter something unexpected, like discovering that an artist doesn’t fit your mental image of their background, lean into the opportunity to learn more.

Ask yourself: Why does this surprise me? What can I learn from this? By staying open and curious, you give yourself the chance to appreciate new experiences without the filter of bias.

A 2021 study published in the Journal of Graduate Medical Education found that self-reflection effectively increased participants’ awareness and knowledge of implicit biases. Researchers found that first impressions based on appearance, ethnicity and stereotypes often led to inaccurate assumptions.

“For a White male physician covered in tattoos, only 2% correctly identified him as a physician, and 60% felt he was untrustworthy. For a smiling Black female astronaut, only 13% correctly identified her as an astronaut. For a brooding White male serial killer, 50% found him trustworthy,” the researchers write, highlighting shocking disparities in stereotypes and reality.

It’s essential to consciously challenge stereotypes when they arise. If you catch yourself making a snap judgment about someone based on their appearance, accent or background, pause and remind yourself that people are complex and multidimensional.

Just because someone doesn’t fit the mold you’re used to doesn’t mean they aren’t incredibly talented or capable. Hanumankind’s success is a reminder that talent transcends borders and by being aware of our biases, we can appreciate the diversity that makes art—and life—so rich.

Wondering how tolerant you are of others’ differences? Take this test to find out: Warm Tolerance Scale

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Independent and Dependent Variables

Saul McLeod, PhD

Editor-in-Chief for Simply Psychology

BSc (Hons) Psychology, MRes, PhD, University of Manchester

Saul McLeod, PhD., is a qualified psychology teacher with over 18 years of experience in further and higher education. He has been published in peer-reviewed journals, including the Journal of Clinical Psychology.

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Olivia Guy-Evans, MSc

Associate Editor for Simply Psychology

BSc (Hons) Psychology, MSc Psychology of Education

Olivia Guy-Evans is a writer and associate editor for Simply Psychology. She has previously worked in healthcare and educational sectors.

On This Page:

In research, a variable is any characteristic, number, or quantity that can be measured or counted in experimental investigations . One is called the dependent variable, and the other is the independent variable.

In research, the independent variable is manipulated to observe its effect, while the dependent variable is the measured outcome. Essentially, the independent variable is the presumed cause, and the dependent variable is the observed effect.

Variables provide the foundation for examining relationships, drawing conclusions, and making predictions in research studies.

Independent Variable

In psychology, the independent variable is the variable the experimenter manipulates or changes and is assumed to directly affect the dependent variable.

It’s considered the cause or factor that drives change, allowing psychologists to observe how it influences behavior, emotions, or other dependent variables in an experimental setting. Essentially, it’s the presumed cause in cause-and-effect relationships being studied.

For example, allocating participants to drug or placebo conditions (independent variable) to measure any changes in the intensity of their anxiety (dependent variable).

In a well-designed experimental study , the independent variable is the only important difference between the experimental (e.g., treatment) and control (e.g., placebo) groups.

By changing the independent variable and holding other factors constant, psychologists aim to determine if it causes a change in another variable, called the dependent variable.

For example, in a study investigating the effects of sleep on memory, the amount of sleep (e.g., 4 hours, 8 hours, 12 hours) would be the independent variable, as the researcher might manipulate or categorize it to see its impact on memory recall, which would be the dependent variable.

Dependent Variable

In psychology, the dependent variable is the variable being tested and measured in an experiment and is “dependent” on the independent variable.

In psychology, a dependent variable represents the outcome or results and can change based on the manipulations of the independent variable. Essentially, it’s the presumed effect in a cause-and-effect relationship being studied.

An example of a dependent variable is depression symptoms, which depend on the independent variable (type of therapy).

In an experiment, the researcher looks for the possible effect on the dependent variable that might be caused by changing the independent variable.

For instance, in a study examining the effects of a new study technique on exam performance, the technique would be the independent variable (as it is being introduced or manipulated), while the exam scores would be the dependent variable (as they represent the outcome of interest that’s being measured).

Examples in Research Studies

For example, we might change the type of information (e.g., organized or random) given to participants to see how this might affect the amount of information remembered.

In this example, the type of information is the independent variable (because it changes), and the amount of information remembered is the dependent variable (because this is being measured).

For the following hypotheses, name the IV and the DV.

1. Lack of sleep significantly affects learning in 10-year-old boys.

IV……………………………………………………

DV…………………………………………………..

2. Social class has a significant effect on IQ scores.

DV……………………………………………….…

3. Stressful experiences significantly increase the likelihood of headaches.

4. Time of day has a significant effect on alertness.

Operationalizing Variables

To ensure cause and effect are established, it is important that we identify exactly how the independent and dependent variables will be measured; this is known as operationalizing the variables.

Operational variables (or operationalizing definitions) refer to how you will define and measure a specific variable as it is used in your study. This enables another psychologist to replicate your research and is essential in establishing reliability (achieving consistency in the results).

For example, if we are concerned with the effect of media violence on aggression, then we need to be very clear about what we mean by the different terms. In this case, we must state what we mean by the terms “media violence” and “aggression” as we will study them.

Therefore, you could state that “media violence” is operationally defined (in your experiment) as ‘exposure to a 15-minute film showing scenes of physical assault’; “aggression” is operationally defined as ‘levels of electrical shocks administered to a second ‘participant’ in another room.

In another example, the hypothesis “Young participants will have significantly better memories than older participants” is not operationalized. How do we define “young,” “old,” or “memory”? “Participants aged between 16 – 30 will recall significantly more nouns from a list of twenty than participants aged between 55 – 70” is operationalized.

The key point here is that we have clarified what we mean by the terms as they were studied and measured in our experiment.

If we didn’t do this, it would be very difficult (if not impossible) to compare the findings of different studies to the same behavior.

Operationalization has the advantage of generally providing a clear and objective definition of even complex variables. It also makes it easier for other researchers to replicate a study and check for reliability .

For the following hypotheses, name the IV and the DV and operationalize both variables.

1. Women are more attracted to men without earrings than men with earrings.

I.V._____________________________________________________________

D.V. ____________________________________________________________

Operational definitions:

I.V. ____________________________________________________________

2. People learn more when they study in a quiet versus noisy place.

I.V. _________________________________________________________

D.V. ___________________________________________________________

3. People who exercise regularly sleep better at night.

Can there be more than one independent or dependent variable in a study?

Yes, it is possible to have more than one independent or dependent variable in a study.

In some studies, researchers may want to explore how multiple factors affect the outcome, so they include more than one independent variable.

Similarly, they may measure multiple things to see how they are influenced, resulting in multiple dependent variables. This allows for a more comprehensive understanding of the topic being studied.

What are some ethical considerations related to independent and dependent variables?

Ethical considerations related to independent and dependent variables involve treating participants fairly and protecting their rights.

Researchers must ensure that participants provide informed consent and that their privacy and confidentiality are respected. Additionally, it is important to avoid manipulating independent variables in ways that could cause harm or discomfort to participants.

Researchers should also consider the potential impact of their study on vulnerable populations and ensure that their methods are unbiased and free from discrimination.

Ethical guidelines help ensure that research is conducted responsibly and with respect for the well-being of the participants involved.

Can qualitative data have independent and dependent variables?

Yes, both quantitative and qualitative data can have independent and dependent variables.

In quantitative research, independent variables are usually measured numerically and manipulated to understand their impact on the dependent variable. In qualitative research, independent variables can be qualitative in nature, such as individual experiences, cultural factors, or social contexts, influencing the phenomenon of interest.

The dependent variable, in both cases, is what is being observed or studied to see how it changes in response to the independent variable.

So, regardless of the type of data, researchers analyze the relationship between independent and dependent variables to gain insights into their research questions.

Can the same variable be independent in one study and dependent in another?

Yes, the same variable can be independent in one study and dependent in another.

The classification of a variable as independent or dependent depends on how it is used within a specific study. In one study, a variable might be manipulated or controlled to see its effect on another variable, making it independent.

However, in a different study, that same variable might be the one being measured or observed to understand its relationship with another variable, making it dependent.

The role of a variable as independent or dependent can vary depending on the research question and study design.