I won't pretend to understand the psychology of the collective, as this is the first I've contemplated it.
I do think that people are mad at their leaders, and don't know what to do about it. People (not just in Britian) are beginning to catch on that 'voting for the other guy' is not enough, in fact is not different, but the same.
Not all people, mind you, maybe I am optimistic of such enlightenment. But I see people around the world eager to do anything besides voting for the 'lesser of two evils', including whatever this Brexit is.
RE: Brexit as suicide: The psychology of self-harm