People need accurate knowledge of others to protect their fragile sense of self.

Evidence

Human beings, if they are to act at all, must define. And if they are to avoid hurts to their fragile selves, they must define with a relatively high degree of accuracy. Yet all the city dweller had to go on, to know anything at all about these other people, was the information he could glean by looking at them. — Lyn H. Lofland, World of Strangers_ Order and Action in…, 131