In psychology, social psychology is the scientific study of how people's thoughts, feelings, and behaviors are influenced by the actual, imagined, or implied presence of others. In this definition, scientific refers to the empirical method of investigation. The terms thoughts, feelings, and behaviors include all psychological variables that are measurable in a human being. The statement that others' presence may be imagined or implied suggests that we are prone to social influence even when no other people are present, such as when watching television, or following internalized cultural norms. Social psychologists typically explain human behavior as a result of the interaction of mental states and immediate social situations.

Social psychologists therefore deal with the factors that lead us to behave in a given way in the presence of others, and look at the conditions under which certain behavior/actions and feelings occur. Social psychology is concerned with the way these feelings, thoughts, beliefs, intentions and goals are constructed and how such psychological factors, in turn, influence our interactions with others.

Social psychology is a discipline that had traditionally bridged the gap between psychology and sociology. During the years immediately following World War II there was frequent collaboration between psychologists and sociologists. However, the two disciplines have become increasingly specialized and isolated from each other in recent years, with sociologists focusing on "macro variables" (e.g., social structure) to a much greater extent. Nevertheless, sociological approaches to social psychology remain an important counterpart to psychological research in this area. Although there were some