Although there were some older writings about social psychology, such as those by Islamic philosopher Al-Farabi (Alpharabius), the discipline of social psychology, as its modern-day definition, began in the United States at the beginning of the 20th century. By that time, though, the discipline had already developed a significant foundation. Following the 18th century, those in the emerging field of social psychology were concerned with developing concrete explanations for different aspects of human nature. They attempted to discover concrete cause and effect relationships that explained the social interactions in the world around them. In order to do so, they believed that the scientific method, an empirically based scientific measure, could be applied to human behavior.
The first published study in this area was an experiment in 1898 by Norman Triplett, on the phenomenon of social facilitation. During the 1930s, many Gestalt psychologists, most notably Kurt Lewin, fled to the United States from Nazi Germany. They were instrumental in developing the field as something separate from the behavioral and psychoanalytic schools that were dominant during that time, and social psychology has always maintained the legacy of their interests in perception and cognition. Attitudes and small group phenomena were the most commonly studied topics in this era.
During World War II, social psychologists studied persuasion and propaganda for the U.S. military. After the war, researchers became interested in a variety of social problems, including gender issues and racial prejudice. Most notable, revealing, and contentious of these were the Stanley Milgram shock experiments on obedience to authority. In the sixties, there was growing interest in new topics, such as cognitive dissonance, bystander intervention, and aggression. By the 1970s, however, social psychology in America had reached a crisis. There was heated debate over the ethics of laboratory experimentation, whether or not attitudes really predicted behavior, and how much science could be done in a cultural context. This was also the time when a radical situationist approach challenged the relevance of self and personality in psychology.
Throughout the 1980s and 1990s social psychology reached a more mature level. Two of the areas social psychology matured in were theories and methods. Careful ethical standards now regulate research. Pluralistic and multicultural perspectives have emerged. Modern researchers are interested in many phenomena, but attribution, social cognition, and the self-concept are perhaps the greatest areas of growth in recent years. Social psychologists have also maintained their applied interests with contributions in the social psychology of health, education, law, and the workplace.