A comment on posts by Katja Grace
The distinction distance
Evolution from distinction difference
Rules of variety
How to explain the strong tendencies people have to be different from each other and yet also to conform? Read the articles to see what that is.

Is it because this makes evolution and cultural change more efficient? I have another idea, based in information theory.

Information theory says that a rare signal brings more information than a common signal, the letter z vs e, for example. The more cars are honking, the less information each honk has. But extremely rare signals are not full of information, as they are basically meaningless. For example, the letter that is in no alphabet, or the car horn honking in a wilderness.

Areas of behavior where we try to avoid extremes of conformity and weirdness are areas where we send messages about ourselves by how we let ourselves be different. Clothing that we choose to wear can send signals about our personality or our background, and also signal that we belong here in this group. In this view, maybe matching another too closely is awkward because it blocks the nonverbal communication.