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The history of psychology is filled with fascinating studies and classic psychology experiments that helped change the way we think about ourselves and human behavior. Sometimes the results of these experiments were so surprising they challengedconventional wisdomabout the human mind and actions. In other cases, these experiments were also quite controversial.Some of the most famous examples include Milgram’s obedience experiment and Zimbardo’s prison experiment. Explore some of these classic psychology experiments to learn more about some of the best-known research in psychology history.
The history of psychology is filled with fascinating studies and classic psychology experiments that helped change the way we think about ourselves and human behavior. Sometimes the results of these experiments were so surprising they challengedconventional wisdomabout the human mind and actions. In other cases, these experiments were also quite controversial.
Some of the most famous examples include Milgram’s obedience experiment and Zimbardo’s prison experiment. Explore some of these classic psychology experiments to learn more about some of the best-known research in psychology history.
1Harlow’s Rhesus Monkey ExperimentsMartin Rogers/Getty ImagesIn a series of controversial experiments conducted in the late 1950s and early 1960s, psychologistHarry Harlowdemonstrated the powerful effects of love on normal development. By showing the devastating effects ofdeprivation on young rhesus monkeys, Harlow revealed the importance of love for healthy childhood development.His experiments were often unethical and shockingly cruel, yet they uncovered fundamental truths that have heavily influenced our understanding of child development.In one famous version of the experiments, infant monkeys were separated from their mothers immediately after birth and placed in an environment where they had access to either a wire monkey “mother” or a version of the faux-mother covered in a soft-terry cloth. While the wire mother provided food, the cloth mother provided only softness and comfort.Harlow found that while the infant monkeys would go to the wire mother for food, they vastly preferred the company of the soft and comforting cloth mother. The study demonstrated that maternal bonds were about much more than simply providing nourishment and that comfort and security played a major role in the formation ofattachments.
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Harlow’s Rhesus Monkey ExperimentsMartin Rogers/Getty ImagesIn a series of controversial experiments conducted in the late 1950s and early 1960s, psychologistHarry Harlowdemonstrated the powerful effects of love on normal development. By showing the devastating effects ofdeprivation on young rhesus monkeys, Harlow revealed the importance of love for healthy childhood development.His experiments were often unethical and shockingly cruel, yet they uncovered fundamental truths that have heavily influenced our understanding of child development.In one famous version of the experiments, infant monkeys were separated from their mothers immediately after birth and placed in an environment where they had access to either a wire monkey “mother” or a version of the faux-mother covered in a soft-terry cloth. While the wire mother provided food, the cloth mother provided only softness and comfort.Harlow found that while the infant monkeys would go to the wire mother for food, they vastly preferred the company of the soft and comforting cloth mother. The study demonstrated that maternal bonds were about much more than simply providing nourishment and that comfort and security played a major role in the formation ofattachments.
Harlow’s Rhesus Monkey Experiments
Martin Rogers/Getty Images
In a series of controversial experiments conducted in the late 1950s and early 1960s, psychologistHarry Harlowdemonstrated the powerful effects of love on normal development. By showing the devastating effects ofdeprivation on young rhesus monkeys, Harlow revealed the importance of love for healthy childhood development.
His experiments were often unethical and shockingly cruel, yet they uncovered fundamental truths that have heavily influenced our understanding of child development.
In one famous version of the experiments, infant monkeys were separated from their mothers immediately after birth and placed in an environment where they had access to either a wire monkey “mother” or a version of the faux-mother covered in a soft-terry cloth. While the wire mother provided food, the cloth mother provided only softness and comfort.
Harlow found that while the infant monkeys would go to the wire mother for food, they vastly preferred the company of the soft and comforting cloth mother. The study demonstrated that maternal bonds were about much more than simply providing nourishment and that comfort and security played a major role in the formation ofattachments.
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Pavlov’s Classical Conditioning Experiments
Hulton Archive / Getty Images
3The Asch Conformity ExperimentsCompassionate Eye Foundation / Getty ImagesResearchers have long been interested in the degree to which people follow or rebel against social norms. During the 1950s, psychologist Solomon Asch conducteda series of experimentsdesigned to demonstrate the powers of conformity in groups.The study revealed that people are surprisingly susceptible to going along with the group, even when they know the group is wrong. In Asch’s studies, students were told that they were taking a vision test and were asked to identify which of three lines was the same length as a target line.When asked alone, the students were highly accurate in their assessments. In other trials, confederate participants intentionally picked the incorrect line. As a result, many of the real participants gave the same answer as the other students, demonstrating how conformity could be both a powerful and subtle influence on human behavior.
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The Asch Conformity ExperimentsCompassionate Eye Foundation / Getty ImagesResearchers have long been interested in the degree to which people follow or rebel against social norms. During the 1950s, psychologist Solomon Asch conducteda series of experimentsdesigned to demonstrate the powers of conformity in groups.The study revealed that people are surprisingly susceptible to going along with the group, even when they know the group is wrong. In Asch’s studies, students were told that they were taking a vision test and were asked to identify which of three lines was the same length as a target line.When asked alone, the students were highly accurate in their assessments. In other trials, confederate participants intentionally picked the incorrect line. As a result, many of the real participants gave the same answer as the other students, demonstrating how conformity could be both a powerful and subtle influence on human behavior.
The Asch Conformity Experiments
Compassionate Eye Foundation / Getty Images
Researchers have long been interested in the degree to which people follow or rebel against social norms. During the 1950s, psychologist Solomon Asch conducteda series of experimentsdesigned to demonstrate the powers of conformity in groups.
The study revealed that people are surprisingly susceptible to going along with the group, even when they know the group is wrong. In Asch’s studies, students were told that they were taking a vision test and were asked to identify which of three lines was the same length as a target line.
When asked alone, the students were highly accurate in their assessments. In other trials, confederate participants intentionally picked the incorrect line. As a result, many of the real participants gave the same answer as the other students, demonstrating how conformity could be both a powerful and subtle influence on human behavior.
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Skinner’s Operant Conditioning Experiments
Bettmann Archive / Getty Images
Skinnerstudied how behavior can be reinforced to be repeated or weakened to be extinguished. Hedesigned the Skinner Boxwhere an animal, often a rodent, would be given a food pellet or an electric shock. A rat would learn that pressing a level delivered a food pellet. Or the rat would learn to press the lever in order to halt electric shocks.
5Milgram’s Obedience ExperimentsIsabelle Adam/Flicker/CC BY-NC-ND 2.0InMilgram’s experiment, participants were asked to deliver electrical shocks to a “learner” whenever an incorrect answer was given. In reality, the learner was actually a confederate in the experiment who pretended to be shocked. The purpose of the experiment was to determine how far people were willing to go in order to obey the commands of an authority figure.Milgramfound that 65% of participants were willing to deliver the maximum level of shocks despite the fact that the learner seemed to be in serious distress or even unconscious.Why This Experiment Is NotableMilgram’s experiment is one of the most controversial in psychology history. Many participants experienced considerable distress as a result of their participation and in many cases were never debriefed after the conclusion of the experiment. The experiment played a role in the development of ethical guidelines for the use of human participants in psychology experiments.
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Milgram’s Obedience ExperimentsIsabelle Adam/Flicker/CC BY-NC-ND 2.0InMilgram’s experiment, participants were asked to deliver electrical shocks to a “learner” whenever an incorrect answer was given. In reality, the learner was actually a confederate in the experiment who pretended to be shocked. The purpose of the experiment was to determine how far people were willing to go in order to obey the commands of an authority figure.Milgramfound that 65% of participants were willing to deliver the maximum level of shocks despite the fact that the learner seemed to be in serious distress or even unconscious.Why This Experiment Is NotableMilgram’s experiment is one of the most controversial in psychology history. Many participants experienced considerable distress as a result of their participation and in many cases were never debriefed after the conclusion of the experiment. The experiment played a role in the development of ethical guidelines for the use of human participants in psychology experiments.
Milgram’s Obedience Experiments
Isabelle Adam/Flicker/CC BY-NC-ND 2.0
InMilgram’s experiment, participants were asked to deliver electrical shocks to a “learner” whenever an incorrect answer was given. In reality, the learner was actually a confederate in the experiment who pretended to be shocked. The purpose of the experiment was to determine how far people were willing to go in order to obey the commands of an authority figure.
Milgramfound that 65% of participants were willing to deliver the maximum level of shocks despite the fact that the learner seemed to be in serious distress or even unconscious.
Why This Experiment Is NotableMilgram’s experiment is one of the most controversial in psychology history. Many participants experienced considerable distress as a result of their participation and in many cases were never debriefed after the conclusion of the experiment. The experiment played a role in the development of ethical guidelines for the use of human participants in psychology experiments.
Why This Experiment Is Notable
Milgram’s experiment is one of the most controversial in psychology history. Many participants experienced considerable distress as a result of their participation and in many cases were never debriefed after the conclusion of the experiment. The experiment played a role in the development of ethical guidelines for the use of human participants in psychology experiments.
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The Stanford Prison Experiment
FilmMagic / Getty Images
Philip Zimbardo’sfamous experiment cast regular students in the roles of prisoners and prison guards. Whilethe studywas originally slated to last 2 weeks, it had to be halted after just 6 days because the guards became abusive and the prisoners began to show signs of extreme stress and anxiety.
It is worth noting criticisms of Zimbardo’s experiment, however. While the general recollection of the experiment is that the guards became excessively abusive on their own as a natural response to their role, the reality is that they were explicitly instructed to mistreat the prisoners, potentially detracting from the conclusions of the study.
8 Sources
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Gantt WH.Ivan Pavlov.Encyclopaedia Brittanica.
Jeon, HL.The environmental factor within the Solomon Asch Line Test.International Journal of Social Science and Humanity.2014;4(4):264-268. doi:10.7763/IJSSH.2014.V4.360
Koren M. B.F. Skinner:The man who taught pigeons to play ping-pong and rats to pull levers.Smithsonian Magazine.
B.F. Skinner Foundation.A brief survey of operant behavior.
Gonzalez-franco M, Slater M, Birney ME, Swapp D, Haslam SA, Reicher SD.Participant concerns for the Learner in a Virtual Reality replication of the Milgram obedience study.PLoS ONE.2018;13(12):e0209704. doi:10.1371/journal.pone.0209704
Le texier T.Debunking the Stanford Prison Experiment.Am Psychol.2019;74(7):823-839. doi:10.1037/amp0000401
Perry G.Deception and illusion in Milgram’s accounts of the Obedience Experiments.Theoretical & Applied Ethics. 2013;2(2):79-92.Specter M.Drool: How Everyone Gets Pavlov Wrong.The New Yorker.2014; November 24.
Perry G.Deception and illusion in Milgram’s accounts of the Obedience Experiments.Theoretical & Applied Ethics. 2013;2(2):79-92.
Specter M.Drool: How Everyone Gets Pavlov Wrong.The New Yorker.2014; November 24.
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