Prescriptive hedonism is the belief that seeking hedonistic pleasure is not just what people do do, but that it is what people should do.
Although hedonism as an accurate description of human motivations on a philosophical level was only taken seriously in England in the 1800's, prescriptive hedonism pops up in day to day discourse to a great, yet unrecognized, extent. If theorists would factor in this great constant pressure on people to act selfishly, it might lead to a reevaluation about to what degree hedonism is a part of human nature.
The examples of the ways this occurs are many, and many of them are trivial. Sometimes these messages to be selfish are not totally wrong, as when a man may be pressured to drop his goal of feeding Africa for a year so that he can get a job and take care of his family. Often, however, this pressure is stupid and immature. On too many occasions I tried to explain to someone why I wouldn't drive a car, or eat meat, or take drugs, or why I wanted to read a book, or why I didn't want to nail or fuck a girl, but wanted to spend time with her and see her happy; only to have people look at me like I was somehow crazy or stupid for worrying about such things.
When someone goes and puts on fancy clothing, to show off to others, that is often written down as a type of hedonism. But unless that person is somehow sexually gratified by looking at themselves, where do they get their pleasure from? From the approval of others. In other words, they are being the very opposite of hedonistic, they are reacting to the pressure of others.