Guttman (Psychiatry/Northwestern) argues that human beings undergo genetically programmed psychological changes in late life that have traditionally equipped them for roles important to the survival of the species and its individual cultures. He contends that modern industrial societies--which provide no important functions for their elders--not only condemn old people to drag out their final years in relative uselessness, but also to suffer a resultant breakdown in family structure and society as a whole. In developing this thesis, Gutmann draws on a wide range of anthropological and psychological studies as well as his own interviews and ""Thematic Apperception Tests"" of members of four ""traditional"" societies: the Navaho, the Druze of Galilee and the Golan Heights, and two Mayan communities in Mexico. His findings reinforce those of an earlier study in Kansas City which found that, in late life, men become less aggressive and more ""feminine,"" while women become more assertive and ""masculine."" These changes, says Guttmann, equip older men for their traditional roles as tenders of the culture, peacemakers, and spiritual leaders, and prepare older women for the role of matriarchs who supervise their extended families. The patriarchal and matriarchal functions have been evolutionally created, he says, to reinforce the customs of society and extended family that, in traditional communities, help young parents during the long ""bondage"" required to transform a helpless human infant into a functioning community member. Without the aid and direction of a strong cultural consensus and a supportive kinship network, the nuclear family often fails in the adequate acculturation of children. This has produced a proliferation of youth crime, self-help groups, and religious sects headed by charismatic ""totalitarian"" leaders. Insightful, mind-stretching, densely documented, and eminently readable.