Social Psychology: Definition, Theories, Principles, & Examples

Social psychology is the scientific study of how people’s thoughts, feelings, beliefs, intentions, and goals are constructed within a social context by the actual or imagined interactions with others.

It, therefore, looks at human behavior as influenced by other people and the conditions under which social behavior and feelings occur.

Baron, Byrne, and Suls (1989) define social psychology as “the scientific field that seeks to understand the nature and causes of individual behavior in social situations” (p. 6).

Topics examined in social psychology include the self-concept, social cognition, attribution theory, social influence, group processes, prejudice and discrimination, interpersonal processes, aggression, attitudes, and stereotypes.

History of Social Psychology

Early Influences

Aristotle believed that humans were naturally sociable, a necessity that allows us to live together (an individual-centered approach), whilst Plato felt that the state controlled the individual and encouraged social responsibility through social context (a socio-centered approach).

Hegel (1770–1831) introduced the concept that society has inevitable links with the development of the social mind. This led to the idea of a group mind, which is important in the study of social psychology.

Lazarus & Steinthal wrote about Anglo-European influences in 1860. “Volkerpsychologie” emerged, which focused on the idea of a collective mind.

It emphasized the notion that personality develops because of cultural and community influences, especially through language, which is both a social product of the community as well as a means of encouraging particular social thought in the individual. Therefore Wundt (1900–1920) encouraged the methodological study of language and its influence on the social being.

Early Texts

Texts focusing on social psychology first emerged at the start of the 20th century. The first notable book in English was published by McDougall in 1908 (An Introduction to Social Psychology), which included chapters on emotion and sentiment, morality, character, and religion, quite different from those incorporated in the field today.

He believed that social behavior was innate/instinctive and, therefore, individual, hence his choice of topics.  This belief is not the principle upheld in modern social psychology, however.

Allport’s work (1924) underpins current thinking to a greater degree, as he acknowledged that social behavior results from interactions between people.

He also took a methodological approach, discussing actual research and emphasizing that the field was one of a “science … which studies the behavior of the individual in so far as his behavior stimulates other individuals, or is itself a reaction to this behavior” (1942: p. 12).

His book also dealt with topics still evident today, such as emotion, conformity, and the effects of an audience on others.

Murchison (1935) published The first handbook on social psychology was published by Murchison in 1935.  Murphy & Murphy (1931/37) produced a book summarizing the findings of 1,000 studies in social psychology.  A text by Klineberg (1940) looked at the interaction between social context and personality development. By the 1950s, a number of texts were available on the subject.

Journal Development

• 1950s – Journal of Abnormal and Social Psychology

• 1963 – Journal of Personality, British Journal of Social and Clinical Psychology

• 1965 – Journal of Personality and Social Psychology, Journal of Experimental Social Psychology

• 1971 – Journal of Applied Social Psychology, European Journal of Social Psychology

• 1975 – Social Psychology Quarterly, Personality and Social Psychology Bulletin

• 1982 – Social Cognition

• 1984 – Journal of Social and Personal Relationships

Early Experiments

There is some disagreement about the first true experiment, but the following are certainly among some of the most important.

Triplett (1898) applied the experimental method to investigate the performance of cyclists and schoolchildren on how the presence of others influences overall performance – thus, how individuals are affected and behave in the social context.

By 1935 the study of social norms had developed, looking at how individuals behave according to the rules of society. This was conducted by Sherif (1935).

Lewin et al. then began experimental research into leadership and group processes by 1939, looking at effective work ethics under different styles of leadership.

Later Developments

Much of the key research in social psychology developed following World War II, when people became interested in the behavior of individuals when grouped together and in social situations. Key studies were carried out in several areas.

Some studies focused on how attitudes are formed, changed by the social context, and measured to ascertain whether a change has occurred.

Amongst some of the most famous works in social psychology is that on obedience conducted by Milgram in his “electric shock” study, which looked at the role an authority figure plays in shaping behavior.  Similarly,  Zimbardo’s prison simulation notably demonstrated conformity to given roles in the social world.

Wider topics then began to emerge, such as social perception, aggression, relationships, decision-making, pro-social behavior, and attribution, many of which are central to today’s topics and will be discussed throughout this website.

Thus the growth years of social psychology occurred during the decades following the 1940s.

Social Psychology Key Figures

Allport (1920) – Social Facilitation

Allport introduced the notion that the presence of others (the social group) can facilitate certain behavior.

It was found that an audience would improve an actor’s performance in well-learned/easy tasks but leads to a decrease in performance on newly learned/difficult tasks due to social inhibition.

Bandura (1963) Social Learning Theory

Bandura introduced the notion that behavior in the social world could be modeled. Three groups of children watched a video where an adult was aggressive towards a ‘bobo doll,’ and the adult was either just seen to be doing this, was rewarded by another adult for their behavior, or was punished for it.

Children who had seen the adult rewarded were found to be more likely to copy such behavior.

Festinger (1950) –  Cognitive Dissonance

Festinger, Schacter, and Black brought up the idea that when we hold beliefs, attitudes, or cognitions which are different, then we experience dissonance – this is an inconsistency that causes discomfort.

We are motivated to reduce this by either changing one of our thoughts, beliefs, or attitudes or selectively attending to information that supports one of our beliefs and ignores the other (selective exposure hypothesis).

Dissonance occurs when there are difficult choices or decisions or when people participate in behavior that is contrary to their attitude. Dissonance is thus brought about by effort justification (when aiming to reach a modest goal), induced compliance (when people are forced to comply contrary to their attitude), and free choice (when weighing up decisions).

Tajfel (1971) –  Social Identity Theory

When divided into artificial (minimal) groups, prejudice results simply from the awareness that there is an “out-group” (the other group).

When the boys were asked to allocate points to others (which might be converted into rewards) who were either part of their own group or the out-group, they displayed a strong in-group preference. That is, they allocated more points on the set task to boys who they believed to be in the same group as themselves.

This can be accounted for by Tajfel & Turner’s social identity theory, which states that individuals need to maintain a positive sense of personal and social identity: this is partly achieved by emphasizing the desirability of one’s own group, focusing on distinctions between other “lesser” groups.

Weiner (1986) – Attribution Theory

Weiner was interested in the attributions made for experiences of success and failure and introduced the idea that we look for explanations of behavior in the social world.

He believed that these were made based on three areas: locus, which could be internal or external; stability, which is whether the cause is stable or changes over time: and controllability.

Milgram (1963) – Shock Experiment

Participants were told that they were taking part in a study on learning but always acted as the teacher when they were then responsible for going over paired associate learning tasks.

When the learner (a stooge) got the answer wrong, they were told by a scientist that they had to deliver an electric shock. This did not actually happen, although the participant was unaware of this as they had themselves a sample (real!) shock at the start of the experiment.

They were encouraged to increase the voltage given after each incorrect answer up to a maximum voltage, and it was found that all participants gave shocks up to 300v, with 65 percent reaching the highest level of 450v.

It seems that obedience is most likely to occur in an unfamiliar environment and in the presence of an authority figure, especially when covert pressure is put upon people to obey. It is also possible that it occurs because the participant felt that someone other than themselves was responsible for their actions.

Haney, Banks, Zimbardo (1973) – Stanford Prison Experiment

Volunteers took part in a simulation where they were randomly assigned the role of a prisoner or guard and taken to a converted university basement resembling a prison environment. There was some basic loss of rights for the prisoners, who were unexpectedly arrested, and given a uniform and an identification number (they were therefore deindividuated).

The study showed that conformity to social roles occurred as part of the social interaction, as both groups displayed more negative emotions, and hostility and dehumanization became apparent.

Prisoners became passive, whilst the guards assumed an active, brutal, and dominant role. Although normative and informational social influence had a role to play here, deindividuation/the loss of a sense of identity seemed most likely to lead to conformity.

Both this and Milgram’s study introduced the notion of social influence and the ways in which this could be observed/tested.



Social psychology provides clear predictions. This means that explanations can be scientifically tested and supported with evidence.

Emphasizes objective measurement

Many experiments support theories


Underestimates individual differences

Ignores biology (e.g., testosterone)

Provides only “superficial snapshots of social processes” (Hayes, 1995)


Allport, F. H. (1920). The influence of the group upon association and thought. Journal of Experimental Psychology, 3(3), 159.

Allport, F. H. (1924). Response to social stimulation in the group. Social psychology, 260-291.

Allport, F. H. (1942). Methods in the study of collective action phenomena. The Journal of Social Psychology, 15(1), 165-185.

Bandura, A., Ross, D., & Ross, S. A. (1963). Vicarious reinforcement and imitative learning. The Journal of Abnormal and Social Psychology, 67(6), 601.

Baron, R. A., Byrne, D., & Suls, J. (1989). Attitudes: Evaluating the social world. Baron et al, Social Psychology . 3rd edn. MA: Allyn and Bacon, 79-101.

Festinger, L., Schachter, S., & Back, K. (1950). Social processes in informal groups.

Haney, C., Banks, W. C., & Zimbardo, P. G. (1973). Study of prisoners and guards in a simulated prison. Naval Research Reviews, 9(1-17).

Klineberg, O. (1940). The problem of personality.

Krewer, B., & Jahoda, G. (1860). On the scope of Lazarus and Steinthals “Völkerpsychologie” as reflected in the. Zeitschrift für Völkerpsychologie und Sprachwissenschaft, 1890, 4-12.

Lewin, K., Lippitt, R., & White, R. K. (1939). Patterns of aggressive behavior in experimentally created “social climates”. The Journal of Social Psychology, 10(2), 269-299.

Mcdougall, W. (1908). An introduction to social psychology. Londres: Methuen.

Milgram, S. (1963). behavioral study of obedience. The Journal of Abnormal and Social Psychology, 67(4), 371.

Murchison, C. (1935). A handbook of social psychology.

Murphy, G., & Murphy, L. B. (1931). Experimental social psychology.

Sherif, M. (1935). A study of some social factors in perception. Archives of Psychology (Columbia University).

Tajfel, H., Billig, M. G., Bundy, R. P., & Flament, C. (1971). Social categorization and intergroup behavior. European journal of social psychology, 1(2), 149-178.

Triplett, N. (1898). The dynamogenic factors in pacemaking and competition. American journal of Psychology, 9(4), 507-533.

Weiner, B. (1986). An attributional theory of motivation and emotion. New York: Springer-Verlag.

Olivia Guy-Evans

BSc (Hons), Psychology, MSc, Psychology of Education

Associate Editor for Simply Psychology

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

Saul Mcleod, PhD

Educator, Researcher

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

Saul Mcleod, Ph.D., is a qualified psychology teacher with over 18 years experience of working in further and higher education.