Most influential psychological experiments

9 Most Influential Psychological Experiments of All Time

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The history of Psychology is filled with strange experiments to order to understand the human brain. This article will talk about the 9 most influential psychological experiments that have defined the field of Psychology.

Influential Psychological Experiments

The field of Psychology is a vast labyrinth of weird but very influential experiments that have shaped the way people understand psychology. In this article, I will talk about the 9 of the most influential experiments that have made a mark on the field of psychology.

Asch Conformity Study

Asch Conformity Study

This study was conducted by Dr. Solomon Asch at Swarthmore College. The study was conducted to see whether a person would conform to a standard when he/she is pressured to do so. In the study, a group of participants was shown photos with lines of various lengths. After that, they were asked which line is the longest?

The tricky part of the study was that there was only one actual participant and the rest were actors. The actors were given instructions to give the wrong answer. Surprisingly, in most cases, the true participant agreed with the rest of the group when they gave the wrong answer.

The results of the study show the importance of our social interactions that we have in society. It also tells us the way an individual can conform to the standards set by a certain group. It also showed people often cared about being the same as others rather than being right.

The Hawthorne Effect

The Hawthorne EffectSource – Cordell Hensley

This study was conducted by Henry A. Landsberger in 1955 at Hawthorne Works in Chicago. The effect’s premise is that people in an experiment change the way they behave and react. The study was conducted between 1924 and 1932 at a factory.

The factory had commissioned the study to see if different levels of lighting affected the efficiency of the production of work. Researchers found no link with the levels of lighting and an increase in workload. But what they did find was that the worker’s level of efficiency increased whenever a new variable was manipulated

This meant that the workers were aware they were under observation and their behavior changed because of that awareness. It was concluded the workers felt important when being observed. The Hawthorne effect has become one of the toughest inbuilt biases to get rid of in the design of any kind of experiment in any kind of research.

Magical Number Seven

magical number seven

This study was conducted by George A. Miller at Princeton University in 1956. It also is known as the ‘Miller’s law’. The argument was that an average human being can hold in his/her working memory around 7 ± 2 objects at a time. This means that the capacity of the human to hold concepts or words falls within the range of 5-9.

The experiment was published in 1956, which detailed the limits of a one-dimensional judgment of our short-term memory.

Pavlov’s Dog Experiment

Pavlov’s Dog ExperimentSource – Age of the Sage

One of the oldest studies, done around the 1890s by Ivan Pavlov. The experiment began with Pavlov and his idea that a dog does not have to learn certain things. In his study, he observed that dogs do not learn to salivate whenever they see food.

He argued rather they are conditioned to do that. He conducted an experiment by using a bell (as a substitute) whenever he gave food to the dogs. After certain repetitions, he just rang the bell. And he found that the dog started to salivate, without the presence of food there.

Pavlov’s experiment with his dogs turned out to be one of the most important experiments in all of the psychology as it paved the way for the behaviorist school within psychology.

False Consensus Effect

False Consensus EffectSource – Econowmics

This study was conducted by Lee Ross at Stanford University in 1977. The intention of the experiment was to focus on how people can form a ‘false consensus’ or believe that others think the way they do.

In the study, participants were asked to read about certain situations in which a conflict occurred and was given two alternative ways to respond to that situation. The study showed that most of the subjects believed that other would do the same.

This phenomenon is known as the false consensus effect when an individual thins that other people think the same when they may not.

Selective Attention – Invisible Gorilla Experiment



This study was conducted by Daniel Simmons and Christopher Chabris at Harvard University in 1999. The participants in the study were asked to watch a video of a group of students passing the basketball. They were asked how many passes were made.

While keeping track of the passes was easy but the students missed was a man dressed in a gorilla walking off the screen. The study found that humans at times overestimate their ability to multi-task. It also calls attention to how we pay attention to certain things and misses other things.

Stanford Prison Study

stanford prison experimentSource – Simply Psychology

One of the most controversial and most cited experiments of all time. It was conducted by Philip Zimbardo at Stanford University in 1971. The Professor wanted to study the role of a position of authority in a prison system.

In the study, college students were recruited to play guards and inmates in a made-up prison. The guards were told to run the prison for 2 weeks. They were told not to harm the prisoners. But however, the guards ended up treating the prisoners badly and started beating them.

The experiment had to be canceled because it went too far. The study showed that human behavior is situational and a person in a position of power is more likely to abuse that position. Lately, it was exposed that the study was rigged and the findings have come in to be questioned but that doesn’t make the study insignificant as it still made an important contribution to human understanding.

The Milgram Experiment

The Milgram Experiment

Source – Johann Savalle

One of the most important experiments in the history of psychology. It was conducted by Stanley Milgram at Yale University in 1961. The study was designed to measure the people’s willingness to obey authority when told to do any kind of work.

Participants were told they were participating in a test about memory. They were asked to the observer and ask questions to other participants and if they got an answer wrong, they’d have to give an electric shock.

The catch was there was no electric shock as the other participant was part of the team. The experimenters kept increasing the levels of shocks despite protests by the person being questioned.

Majority of the participants kept giving the shocks when told to do so. The experiment showed that humans are conditioned to obey authority and most likely do what they are told to do so, even if it is against common sense or their moral nature.

To Conclude

Here you go, 9 of the most influential psychological experiments of all time. Now, some landed in hot waters like for instance the Stanford Prison experiment, being called a fraud. But nevertheless, these experiments made different contours in the overall journey of Psychology as a field of study. For now, cheer and keep exploring yourself with Brainpundits.

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