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Famous Psychology Experiments to Study

Published on: May 3, 2022

animation of a person's brain surrounded by DNA

What we know about human psychology today comes from a number of tests, experiments and research projects that explored the way humans think, behave and interact with one another. Historically, many of these projects pushed the ethical limits of the day and may not be something we can repeat. Yet studying their results gives us amazing insight into the human mind. From mood disorders like depression to discovering how people interact with groups, ground-breaking psychological experiments are fascinating to study.

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Why Is Research Important in Psychology?

Unlike biology and chemistry, much of psychology is a social or “soft” science. The ideas and feelings of the human mind are not something researchers can easily measure or repeat in a laboratory. Thus, they are not always something people can predict.

Psychology experiments are invaluable because it gives psychologists the chance to observe and study human behavior. Carefully designed research studies can provide insight into how physiological disorders work and who might be more at risk for them. These studies can provide insight into how people build and grow relationships, how children develop and build bonds, and much more. Psychology studies can also show how psychological health and mental disorders affect individuals and society as a whole. In the case of mental health concerns, it is through research that psychologists find effective treatments to help improve the quality of life for people who are struggling.

Types of Psychology Research Methods

Psychology research falls into one of three basic categories:

Descriptive: Simply describes the features of a group or behavioral phenomena but does not look at how, when, or why.

Correlational: Looks for statistical connections between pieces of data or variables in the test or experiment.

Experimental: Uses proven scientific methods to explore psychology and what drives behavior and mental health.

Experimental psychology is typically where tests and experiments take place. These psychologists use test subjects to study issues in the field.

Influential and Famous Psychology Experiments

The research and experiments of the psychologists of the past have given the field tremendous insight into a wide range of topics. Many experiments pushed the envelope of ethics, often putting people in distressing or difficult scenarios that would not be allowed today. Yet they did bring new knowledge to the field. Here are some of the experiments that are still impacting the world of psychology and mental health treatment today.

Developmental Psychology Experiments

Developmental psychology studies the development, change and consistency of an individual's mental abilities and psychological well-being throughout their life. Developmental psychology often looks at the development of children and their thoughts, feelings and behaviors. Some historical psychological studies have provided insight into child development that professionals still use today.

Little Albert and the Rat – In the early 1900s, psychologist John Watson did experiments on a newborn to see if he could create a fear of rats. He exposed a nine-month-old baby boy who was not afraid of rats to the creatures while making a loud noise. Soon, the baby associated rats with the noise and became afraid of them.

Bobo Doll Experiment – In the early 1960s, psychologists were fascinated with the question of nature versus nurture in child development. This particular experiment studied how aggressive children were when watching other children. Albert Bandura and a team of researchers exposed 24 kids to a group of adults who were acting aggressively toward a doll called Bobo. Another group watched the adults play with the doll nicely, while the final group didn’t see the doll.

After the observation, the children were placed into different scenarios, such as having researchers give them toys to play with, take toys away, or give them aggressive toys, like mallets or toy guns. Bandura and his team found that children who saw aggression toward the Bobo doll were more likely to show aggression in their own play than those who did not observe aggressive adults. They then theorized that social imitation drives human behavior more than human genetics.

Fantz’z Looking Chamber – Robert L. Fantz carried out an experiment in 1961 that showed important insight into infant development and vision. Before his experiment, researchers had few thoughts on how to study the developing mind of a newborn. In his experiment, Fantz placed newborns into a box and showed them two patterns on the ceiling above them, one of a bull’s eye and one of a human face. Researchers found that babies as young as two months had a clear preference for looking at the human face, which showed humans have an in-born ability to recognize human faces.

Surrogate Mother Experiment – Psychologist Harry Harlow developed a series of studies in the late 1950s and early 1960s to determine the role of a mother’s love in the development of a child. He used young rhesus monkeys for his experiment, separating the babies from their birth mothers and giving them to two surrogates. One surrogate was simply wire and wood with a bottle connected to it, while the other was a plush terrycloth with no food. Researchers found that the baby monkeys spent significantly more time with the soft, plush “mother” than with the one that had food. He then placed monkeys in various new situations, and only those infant monkeys who had a plush surrogate were confident enough to explore scary situations. Harlow theorized that love and nurture and the parent-child relationship were vital to the development of a baby.

Social Psychology Experiments

Social psychology explores the impact others have on an individual's ideas, feelings and behaviors. This impact can be due to both the real presence of other people or the implied presence of society or a group as a whole, even without their physical presence. These famous social psychology experiments have greatly impacted the understanding of sociology.

The Good Samaritan Experiment – In the Good Samaritan Experiment, students were given religious education, then were asked to go from one building to the next. Researchers placed a man acting like he was wounded and in need of help between the two buildings. If the group of students was not pressed for time, almost two-thirds of the students stopped to help the actor. Only 1 in 10 was willing to do so when the researchers put them on a deadline.

To add to the experiment, researchers gave one group the task of going to the next building to make a speech on helping others. This change increased the chances that they would stop to help by almost two times. The conclusion was that people’s ideas had a significant impact on whether or not they were willing to help others.

Robbers Cave Experiment – Researchers from the University of Oklahoma performed this experiment in 1954. They created two groups of pre-teen boys, then sent them to summer camp. After spending a week with just their cabin mates, the groups came together for some activities and competitions.

The groups were clearly biased and antagonistic with the members of the other group. When the researchers tried to increase their time together to reduce this prejudice, the prejudice got worse. It was not until the groups were given a task on which to work together that the tension eased. Researchers theorized that group conflict often occurs when groups must compete over necessary resources.

Ross’ False Consensus Effect Study – Lee Ross, a social psychology professor at Stanford University, ran an experiment in 1977 that looked at the way people make wrong assumptions, or a “false consensus,” about others and their preferences. He did two studies to draw these conclusions.

First, Ross and his associates asked participants to read about conflict and guess how people would respond. Most participants guessed that others would respond the same way they did. Next, Ross asked participants to walk around campus wearing a sign that said, “Eat at Joe’s.” Subjects were told they would get a reward if they wore the sign. They then asked how many of the study participants they thought would also agree to wear the sign. Over half felt that others would make the same choice they did. Based on these two studies, Ross theorized that people naturally assumed others around them would make the same choices they did.

The Milgram Experiments – Stanley Milgram performed a series of obedience tests in 1963 that had rather frightening parameters. In his experiment, he asked volunteers to apply severe electrical shocks to another person. The shocks did not actually hurt, but the other person acted as if they were in severe pain. Even in this difficult scenario, 65% of the participants were willing to obey the experimenter and inflict pain on the other person. Based on these results, Milgram theorized that many of those people who committed horrible crimes in World War II justified their actions because they were just “obeying orders.”

Controversial and Unethical Psychology Experiments

Many psychology experiments in the past did not follow good ethical parameters. Though the results have helped our understanding of psychology today, the methods remain questionable. In addition to experiments like The Milgram Experiments or Little Albert and the Rat, which have already been mentioned, here are fascinating and sometimes disturbing psychology experiments:

Seligman’s Investigation and Learned Helplessness – In this classic experiment, Seligman placed dogs in a box with two chambers, one of which had an electrified floor. If dogs were placed in the box after being administered electrical shocks they could not predict or control, then those dogs would not attempt to get away from the shocking floor. Dogs that had not been shocked prior to going in the box would quickly jump over the barrier to avoid the floor. This led to the theory of learned helplessness, which postulates that people who were once in helpless situations may not attempt to improve their current situation, even if they can.

The Monster Study – The Monster Study in 1939 took a group of children with speech impediments and tested whether positive or negative reinforcement worked best. Some children were given praise for fluency, while the other was given severe treatment for speech problems. Those who received negative reinforcement actually stopped speaking, while those who were given praise were able to improve their speech.

The Aversion Project – From 1971 to 1987, researchers in South Africa imprisoned homosexual men and women in a military hospital. They performed aversion treatment, which was a form of torture, to try to get these individuals to change their sexual identities. Few positive results occurred, and many of the forced participants either died due to treatment or due to suicide after the program ceased.

Stanford Prison Study – In the Stanford Prison Study of the 1970s, participants were placed in a fabricated prison environment. Some were assigned the role of guard, while others were assigned the role of an inmate. The guards were given a tremendous amount of control over the inmates, performing horrific punishments on them. Many inmate participants experienced paranoia as the cruelty of the guards increased. The experiment only lasted six days, but it showed that human behavior is quite situational, and people will quickly fall into an assigned role if the conditions are right.

Learn More About Human Behavior With a Degree in Psychology

Psychology continues to grow as a profession and a field. Though there have been questionable studies in the past, today there are clear guidelines and ethics that control this field. If you are interested in studying human thought and behavior, check out Husson University's online psychology degree today.

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