How Sexist Men Profit

Conversely, traditional men regard themselves as breadwinners, so they work hard and expect to be rewarded accordingly, and that, the researchers conclude, "evokes behaviors that bring about that very outcome." It's a self-fulfilling prophesy. If you're the man, you'd better prove it, and one way to do that is to bring home a fat paycheck.

The researchers say the effect of gender attitudes on income has been largely overlooked. And they concede that those attitudes are changing.

"When workers' attitudes become more traditional, women's earnings relative to men suffer greatly," Judge said in releasing the study. "When attitudes become more egalitarian, the pay gap nearly disappears."

So, if this study is on target, it's not just what you do for a living that determines your income. It's also what you think about your gender.