The WU I was responding is no longer here. But, I am.
We have nothing but our precieving to base judgement on.
Thus, we must judge people on our perceptions of them. There really and truely is no other choice.
If your preconcieved concepts of people get in the way of your understanding them, this is a bad thing. But preconceptions are quite different from preceptions.
Our perceptions may indeed be imperfect. But an imperfect understanding still beats random guessing by a long shot.
Perception is only as good as the perceiver.