A clear and lucid account of the science and debate involving the differences between men and women. It is a well-balanced account of the arguments and evidence. The upshot is that men and women do differ on average, but that the differences are usually modest. In comparison with other animals, we seem to occupy a somewhat awkward position where sexual differences are significant but do not entirely dominate our behavior. The author concludes that while the behavioral and social differences are significantly modulated by culture, there is an innate component that is difficult to explain away.