'The most common of all follies,' wrote H. L. Mencken, 'is to believe passionately in the palpably not true. It is the chief occupation of mankind.' … - Steven Pinker

But among many professional women the existence of sex differences is still a source of discomfort. As one colleague said to me, "Look, I know that males and females are not identical. I see it in my kids, I see it in myself, I know about the research. I can't explain it, but when I read claims of sex differences, steam comes out of my ears."

The human brain is an exquisitely complex organ that evolved only once. The elephant's trunk, which can stack logs, uproot trees, pick up a dime, remove thorns, powder the elephant with dust, siphon water, serve as a snorkel, and scribble with a pencil, is another complex organ that evolved only once.

Suppose the reasoning centers of the brain can get their hands on the mechanisms that plop shapes into the array and that read their locations out of it. Those reasoning demons can exploit the geometry of the array as a surrogate for keeping certain logical constraints in mind. Wealth, like location on a line, is transitive: if A is richer than B, and B is richer than C, then A is richer than C. By using location in an image to symbolize wealth, the thinker takes advantage of the transitivity of location built into the array, and does not have to enter it into a chain of deductive steps. The problem becomes a matter of plop down and look up. It is a fine example of how the form of a mental representation determines what is easy or hard to think.