Reproductive constraints on dominance competition in male Homo sapiens

Dominance competition among males of the same group is characteristic for most primates including humans, with the outcome-rank-being positively associated with fitness. However, because we do not observe an evolutionary arms race toward hyperdominance in primate social systems, the evolution of ever more dominating behavior characteristics may be checked by increased costs in fitness to top rank. Empirical evidence for such costs, particularly in humans, however, is almost nonexistent. Here, for the first time, we can demonstrate for a cohort of male humans, military officers, all graduates of the class of 1950 of the U.S. Military Academy, constituting a closed and cohesive social group, that competitive qualities leading to top rank may have a negative effect on fitness. (C) 1998 Elsevier Science Inc.