Observations were made following spontaneous aggressive incidents in a breeding group of captive stumptail macaques (Macaca arctoides). Participants were observed both during the first 10 min following the aggressive incident, and during matched-control observations. Data on 670 pairs of former opponents were collected, and compared with a sample of 573 such pairs of rhesus macaques (M. mulatta), which had been observed with identical methods in a previous study. Selective attraction between opponents was confirmed for the stumptail monkeys, i.e. both the absolute and the relative rate of nonagonistic body contact between individuals increased after aggression between them. The species was found to be considerably more conciliatory than rhesus monkeys, and to have a remarkably rich repertoire of reassurance gestures. The most characteristic conciliatory behavior is the hold-bottom ritual, in which one individual (usually the subordinate) presents its hindquarters, and the other (usually the dominant) clasps the other's haunches. The high rate of reconciliation among stumptail monkeys extended to all relationship classes, and a correlation with the closeness of social bonds (measured as time spent in association) could not be demonstrated. Because of the generality of the species' high peacemaking tendencies it is assumed that group cohesiveness is of great survival value in the wild.