related to the study of group dynamics, as most effects of influence are strongest when they take place in social groups. The first major area of social influence is conformity. Conformity is defined as the tendency to act or think like other members of a group. The identity of members within a group (i.e., status), similarity, expertise, as well as cohesion, prior commitment, and accountability to the group help to determine the level of conformity of an individual. Individual variations among group members play a key role in the dynamic of how willing people will be to conform. Conformity is usually viewed as a negative tendency in American culture, but a certain amount of conformity is adaptive in some situations, as is nonconformity in other situations. The second major area of social influence research is compliance, which refers to any change in behavior that is due to a request or suggestion from another person. The foot-in-the-door technique is a compliance method in which the persuader requests a small favor and then follows up with a larger favor (e.g., asking for the time and then asking for ten dollars). A related trick is the bait and switch, which is a disingenuous sales strategy that involves enticing potential customers with advertisements of low-priced items which turn out to be unavailable in order to sell a more expensive item. The third major form of social influence is obedience; this is a change in behavior that is the result of a direct order or command from another person. Obedience as a form of compliance was dramatically highlighted by the Milgram study, wherein people were ready to administer shocks to a person in distress on a researcher's command. An unusual kind of social influence is the self-fulfilling prophecy. This is a prediction that, by being made, causes itself to become true. For example, in the financial field, if it is widely believed that a crash is imminent, investors may lose confidence, sell most of their stock, and thus cause a crash. Similarly, people may expect hostility in others and induce this hostility by their own behavior. Psychologists have spent decades studying the power of social influence, and the way in which it manipulates people's opinions and behavior. Specifically, social influence refers to the way in which individuals change their ideas and actions to meet the demands of a social group, received authority, social role, or