Social psychology is the branch of psychology that studies individuals as they interact with others. One topic of interest to social psychologists is the influence that others have on individual behavior. Among the group processes discussed are deindividuation, social loafing, social facilitation, social impairment, group polarization, and groupthink.

Social psychologists have also studied group phenomena such as our tendency to conform to group pressure, the importance of social roles in our lives, and our tendency to obey authority figures.

Attitudes are beliefs that predispose us to behave in certain ways. Attitudes are learned from direct experience and from others. The persuasiveness of messages is determined by the characteristics of the speaker (credibility, attractiveness, and intent), the message (fear appeals and two-sided arguments), and the listeners (intelligence, need for social approval, esteem, and audience size). People are persuaded by such techniques as the "foot-in-the-door" and by "low-balling".

Cognitive dissonance theory has been proposed to explain the process of attitude change. According to Festinger, when behavior and attitudes are inconsistent, attitudes often change to match the behavior rather than the other way around.

Prejudice is a negative attitude based on inaccurate generalizations about a group of people. The inaccurate generalization on which the prejudice is based is called a stereotype. Stereotypes are harmful because they take away our ability to treat each member of a group as an individual and because they lead to faulty attributions.

Friendship and love are powerful social phenomena based on the process of person perception. The process of person perception is complicated by the ways in which we gather and use information about others. Different people will perceive the same individual differently because of differences in interpreting the individual's characteristics. Negative information is generally weighted more than positive information in person perception. First impressions, also known as the primacy effect, generally influence person perception more than information learned about the person at a later date. Prolonged exposure to the person, the passage of time, and knowledge about primacy effects all can reduce the effects of the primacy effect. Person perception is also influenced by the emotional state of the perceiver.

Social behavior is strongly influenced by the attribution process. The fundamental attribution error involves our tendency to underestimate the impact of situations on others while more easily seeing its impact on ourselves. Although many factors ensure that each individual's perception of an individual will be unique, there are some general factors that partly determine to whom we will be attracted: proximity, similar and complementary characteristics, competence, physical attractiveness, and mutual liking. The attribution process is also involved in the perception of others. One aspect of the attribution process is deciding if a person's behavior is caused by the situation (a situational attribution) or by a trait of the person (a dispositional attribution).

Two major factors that determine whether a relationship will last are the differences between what you expect to find in a relationship and what you actually find, and the degree to which the relationship is equitable.

According to Susan Fiske, there are three sources of gender-based job discrimination (1) evaluations of job performance are influenced by gender stereotypes; (2) narrow expectations for behavior created by stereotypes lead to discrimination; and (3) faulty attributions based on gender stereotypes operate in the workplace.