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.