Geoffrey Miller is a man with a theory that, if true, will change the way people think about themselves. His idea is that the human brain is the anthropoid equivalent of the peacock's tail. In other words, it is an organ designed to attract the opposite sex.
...In the romantically primed group, the men went wild with the Monopoly money. Conversely, the women volunteered their lives away. Those women continued, however, to be skinflints, and the men remained callously indifferent to those less fortunate than themselves. Meanwhile, in the other group there was little inclination either to profligate spending or to good works. Based on this result, it looks as though the sexes do, indeed, have different strategies for showing off. Moreover, they do not waste their resources by behaving like that all the time. Only when it counts sexually are men profligate and women helpful.
One of Tyler Cowen's criticisms of Robin Hanson, which I believe is stated in this interview, is that Robin wants to reduce too much behavior to signals related to mating. One of the most annoying things about Hanson is that criticisms of him that appear to be wise often aren't. Don't let him see this story.