There are many things that influence human behavior, one of the biggest is that of other people. The field of social psychology looks at and studies "human behavior as influenced by other people and the social context in which this occurs" (McLeod, 2008). There is a wide variety of ways that people can influence the behaviors of others, most often in the form of a set of social expectations. There are particular expectations, or "proper" ways of behaving, for all the different types of social situations and we expect people to act in accordance with these (Kowalski & Westen, 2011). Sometimes the expectations are subtle, as in the roles that a man or a woman should play. At other times, we can more easily see the social influence, like the growing number of people who have been diagnosed with eating disorders. In both gender roles and eating disorders, the social influence can great.
The first forms of social influence we see on the gender roles of men and women comes from their parents. The parents choose toys based on the gender of the child and will encourage them to engage in activities that are considered normal for the child's gender. The parents will also use reinforcement, positive and negative, in order to strengthen those behaviors that they see as appropriate for the child's gender. For example, parents will reward a daughter for playing tea party with her dolls but a son would be punished. Many fathers engage in "roughhousing" with their sons, teaching them aggression is okay for their gender. A typical father would not consider doing this with his daughter, it is not considered appropriate for girls to display aggressiveness. Another source of social influence on gender roles comes when the child enters school. School provides a setting for children to interact with each other, allowing a greater influence on their behavior. A child's classmates act as models of appropriate behavior for their gender, and like parents, they reward appropriate behavior and punish inappropriate behavior.