International Journal of Primatology, Vol. 11, No. 2, 1990 Social Relationships and Ritualized Greetings in Adult Male Baboons (Papio cynocephalus anubis) Barbara B. Smuts 1 and John M. Watanabe 2 Received November 29, 1988; revised May 25, 1989 Greetings involving exchanges of ritualized sexual gestures are a common form of interaction among adult male baboons, although relatively little at- tention has been paid to them. In this study, we investigate how greetings reflect important aspects of the male's social relationships, including dominance rank, age/residence status, and cooperative tendencies. The results are based on over 600 greetings among 12 adult males recorded during a 4-month study of a troop of wild olive baboons near Gilgil, Kenya. Four of the adult males were older, lower-ranking, long-term residents, which fre- quently formed coalitions to take estrous females away from the eight young, higher-ranking males. Virtually all dyads greeted: greetings occurred more than twice as often as other types of male-male interactions; and nearly all greetings occurred in a neutral context, in which there was no resource at stake. The percentage of greetings completed, the frequency with which differ- ent gestures were employed, and the roles adopted by each male varied sig- nificantly across old-old, old-young, and young-young dyads. Greetings between young adult males were often interrupted or actively resisted, con- sistent with their unstable and ambiguous dominance relationships. Greet- ings between old-old dyads were usually completed and appeared consistent with their cooperative relationships. One pair of old males formed a stable, reciprocal coalition against young males, and this pair's greetings showed remarkable symmetry of roles. Greetings, we hypothesize, function to allow 1 Department of Psychology and Department of Anthropology, University of Michigan, 580 Union Drive, Ann Arbor, Michigan 48109-1346. 2 Department of Anthropology, Dartmouth College, Hanover, New Hampshire 03755. 147 0164-0291/90/0400-0147$06.00/0 © 1990 Plenum Publishing Corporation