Social Psychology Experiments

Famous Experiments in Social Psychology

Social Psychology ExperimentsFamous social psychology experiments and studies have influenced  the field itself as well as public understanding of human nature.

The Bennington College study was conducted by sociologist Theodore Newcomb from 1935 until 1939. The study examined the attitudes of students attending the then all-female Bennington College early in the college’s history; indeed, the study began during the first year that the college had a senior class.

Solomon Asch’s Conformity experiments in the 1950s starkly demonstrated the power of conformity on people’s estimation of the length of lines. On over a third of the trials, participants conformed to the majority, even though the majority judgment was clearly wrong. Seventy-five percent of the participants conformed at least once during the experiment.

In Muzafer Sherif ’s Robbers Cave experiment (1954) boys were divided into two competing groups to explore how much hostility and aggression would emerge. It is also known as realistic group conflict theory, because the intergroup conflict was induced through competition over resources.

Leon Festinger’s Cognitive Dissonance experiment subjects were asked to perform a boring task. They were divided into two groups and given two different pay scales. At the end of the study, participants who were paid $1 to say that they enjoyed the task and another group of participants were paid $20 to say the same lie. The first group ($1) would later believe that they like the task better than the second group ($20). People justified the lie by changing their previously unfavorable attitudes about the task (Festinger and Carlsmith 1959).

Stanley Milgram’s Obedience to Authority experiment has shown how far people would go to obey an authority figure. Following the events of the Holocaust in World War II Stanley Milgram’s experiments of the 1960s/1970s showed that normal American citizens were capable of following orders to the point of causing extreme suffering in an innocent human being.

Albert Bandura’s Bobo Doll experiment has demonstrated how aggression is learned by imitation (Bandura et al. 1961). Bandura’s experimental work was one of the first studies in a long line of research showing how exposure to media violence leads to aggressive behavior in the observers.

In Philip Zimbardo’s Stanford Prison experiment a simulated exercise between student prisoners and guards showed how far people would follow an adopted role. This was an important demonstration of the power of the immediate social situation, and its capacity to overwhelm normal personality traits (Haney et al. 1973).

Experimentation in Social Psychology

Experimentation Definition

In its simplest form, experimentation is a method of determining the presence or absence of a causal relationship between two variables by systematically manipulating one variable (called the independent variable) and assessing its effect on another variable (called the dependent variable).

Importance and Consequences of Experiments

The hallmark of experimentation is that it allows researchers to make statements about causality. There are several features of experiments that facilitate such claims:

  1. Experiments allow researchers to create a situation in which changes in the independent variable precede assessment of the dependent variable—making it possible to draw conclusions about the directionality of the relationship. This is important, because to establish a cause-and-effect relationship between two events, the event that one supposes to be the cause must precede the event that one supposes to be the effect.
  2. Experimentation entails randomly assigning participants to experimental groups. When random assignment is employed, each participant has an equal chance of being assigned to any of the experimental conditions in a study. This technique allows researchers to assume that the experimental groups of participants are equivalent at the outset of the study. Thus, researchers can safely attribute any observed differences in the dependent variable to the experimental manipulation without worrying about the possibility that naturally occurring differences between the groups of participants could account for these differences. For example, suppose that a researcher wants to determine whether playing chess causes an increase in creativity among fifth graders. Imagine that the researcher decides to have two groups: one group that plays chess for an hour after school each day for 6 months and a control group that has free time for an hour after school each day for 6 months. At the start of the study, the researcher recruits a group of 80 fifth graders and allows them to sign up to either play chess or get free time. Six months later, the researcher gives all the kids a creativity test. Sure enough, the researcher finds that the 12 kids who chose playing chess scored higher on the creativity test than the 68 kids who chose free time. Can the researcher say that chess caused an increase in creativity? No—because the kids who chose to play chess might have been more creative than those who chose free time. Thus, the group differences in creativity may have been there from the start and may have had nothing to do with the researcher’s manipulation. To do this experiment properly, the researcher should randomly assign the students to a condition, so that 40 played chess and 40 had free time. By doing so, the researcher could assume that the two groups were equivalent at the start of the study, and so any differences in creativity at the end of the study could be attributed to the independent variable (in this case, playing chess vs. having free time) and not to differences in creativity that existed before the study began.
  3. Experimentation allows researchers to isolate the effect of the independent variable by controlling all other elements of the environment, thereby ensuring that all of the participants in a given study undergo a similar experience, with the exception of the experimental manipulation. In the chess versus free time example, imagine that the kids in the chess group always listened to classical music while they played chess, whereas the kids in the free time group did not listen to music. At the end of the study, could the researcher be sure that the difference in creativity between the two groups was due to the game that they played? No—because whether the kids listened to classical music also may have influenced their creativity. To do the experiment properly, the two groups should be identical with the sole exception of the independent variable (chess vs. free time). In this way, the experimenter could be sure that it was really the independent variable that influenced the student’s creativity and not some other factor.

Some scholars have questioned the utility of experimentation, noting that the experiments which researchers design sometimes do not resemble the circumstances that people encounter in their everyday lives. However, experimentation is the only research method that allows one to definitively establish the existence of a causal relationship between two or more variables.


  1. Goodwin, C. J. (2003). Research methods in psychology: Methods and design. New York: Wiley.
  2. Pelham, B. W. (1999). Conducting research in psychology: Measuring the weight of smoke. Pacific Grove,CA: Brooks/Cole.