Hot on the trail laid down by Lorenz, Ardrey, and their ilk, a Canadian anthropologist here investigates the role of all-male groups (cliques, fraternities, work teams) and their relation to man's genetic inheritance. Underlining the importance of exclusively male configurations in all human and some primate societies, Tiger sees the inclination to ""male-bond"" as a mark of homo sapiens, genetically imprinted since the days of hunting cultures, and vital to community survival. But male bonding has evil effects too: the same groups which conduct the community's political and economic affairs and validate masculine standards also stimulate male tendencies to make war. Undergirded by sizable erudition, this analysis has some merit. It continues the current movement toward an interdisciplinary science of behavior, and opens the way to further research on sex roles, about which the author has some fresh and interesting ideas. But it also has some near-fatal flaws. The biological basis for male-bonding is never proven--there is no evidence. The discussion focuses far too heavily on men in Western cultures. And the insistence on biological-historical (rather than sociocultural or psychoanalytic) explanation gives the book an odd slant: these ""men in groups"" are exclusively motivated by atavism; they do not spring from mothers and fathers, nor are they much affected by the specific mores of their community. This type of argument unweights the needed balance between nature-nurture approaches. Hopefully it will be righted by later works, which may also be more accessible to the general reader.