Do People really feel to be a part of a group or does society make them feel so? People who refuse to adhere themselves to a group are usually seen as a weirdo. This often forces people to join a group despite a want to not to. This fear of being labeled as a weirdo causes people to do things that they may not want as well. To be in the group they must adhere to its rules; all the while remaining normal. However, the ones who remain out of any sort of group are alienated and demonized.
Groups are essential for people who are uncomfortable doing certain things on their own. The fact that they can share their behavior with others who condone it allow a boost in their confidence. Whether the actions be benign or dangerous the fact that they can share the action adds normalcy to it. This is much like the gang initiations where a person must endure a pummeling by gang members. Since when is it normal to endure such a thing voluntarily? That is just plain stupidity, however, they think 'well he, she, and they did it so its fine'.
The want to adhere to a group is a dangerous occupation and just plain stupid because it makes you lose sense of self. A group is just that and you are not allowed to be yourself, you are at the mercy of the group's "great design".