I suppose adults (around 20 years and onward) are the most productively discussable age group, as by then the mind has completed most of its development.

I can only think sadism the reason for why one would pretend to be someone's friend, unless affirming the "absurdity" of the concept itself reinforces a status divide.

The pin incident points to in-groups using exclusionary measures to define themselves from everyone out-group.

Just conceived theory:
In school settings, groups of girls that signal unavailability and attract the majority of their class's opposite sex maintain these two measures of status through exclusively signalling themselves as what 'high-status' means. These signals often express themselves as psychological games.
The theory would extrapolate to post-school settings by essentially repeating the process; have others signal one as high-status by treating one as such, then represent oneself as the epitome of high-status by using similar games to signal others as lower status.

The theory operates on the premise that the games are all about status, which I think would be sad if true. So specious.