Here’s a great quote from Walter Lippmann, author of “Public Opinion.” When he talks about stereotypes, he’s not just talking about being racist — he means all of the subconscious assumptions we make about how the world works:

What matters is the character of the stereotypes, and the gullibility with which we employ them. And these in the end depend upon those inclusive patterns which constitute our philosophy of life. If in that philosophy we assume that the world is codified according to a code which we possess, we are likely to make our reports of what is going on describe a world run by our code. But if our philosophy tells us that each man is only a small part of the world, that his intelligence catches at best only phases and aspects in a coarse net of ideas, then, when we use our stereotypes, we tend to know that they are only stereotypes, to hold them lightly, to modify them gladly. We tend, also, to realize more and more clearly when our ideas started, where they started, how they came to us, why we accepted them. All useful history is antiseptic in this fashion. It enables us to know what fairy tale, what school book, what tradition, what novel, play, picture, phrase, planted one preconception in this mind, another in that mind.

Well said.