This husband and wife team pool their respective talents as psychiatrist and anthropologist in a slightly flaky research job into the ""biological underpinnings"" of impotence and frigidity. You might have thought that Social Darwinism had breathed its last, but the Jonases argue that procreative success is a psychological function of the law of natural selection. Though they note that mankind is the only species subject to this sort of malfunction, their parallelistic explanation sees the behavior of fiddler crabs and hammerhead fruit bats as evolutionary models for human bonding. They go on to define love as an a priori strict dichotomy of the maternal tenderness experienced in infancy and the primordial passionate need to dominate. For the Jonases it's the need to dominate that counts. Impotence is thus nothing more than a secondary manifestation of a weak drive for status or lack of aggressive competitiveness. Human losers can presumably be transformed into winners in bed by exercising their aggression. As for those feelings of tenderness, ""our sexuality has engulfed a large part of our sensuality."" One of the marvels of interdisciplinary social science is that you can build such an awesome house of cards out of so few unverifiable generalizations.