What we learn about women from research vs. what we learn from evolutionary psychology speculation

An interesting study on female aggression points out the trouble with making declarations about inherent human nature based on speculation about sexual dynamics. New studies, including this one, are finding that women can be plenty competitive and aggressive. At The New York Times, John Tierney points out that old ideas about female passivity were based on "an evolutionary analysis of the reproductive odds in ancient polygynous societies in which some men were left single because dominant males had multiple wives".