Barkow, J.H., Cosmides, L. & Toobey, J. The Adapted Mind. New York: Oxford University Press (1992). A less academic and more accessible presentation of some of the same ideas can be found in Steven Pinker, How the Mind Works. (W.W. Norton & Co., N.Y. 1997). An introduction to evolutionary psychology by Toobey and Cosmides is available online.