Female baboons do not raise the stakes but they give as good as they get

We used data from four chacma baboon, Papio cynocephalus ursinus, troops, l iving in two populations, to test the raise the stakes (RTS) strategy of re ciprocity. Female baboons did not raise the stakes either within or across grooming bouts. Instead they time-matched grooming contributions and divide d grooming into short episodes. In addition, analysis of the grooming behav iour of frequently versus infrequently grooming dyads did not reveal differ ences in grooming patterns predicted by the RTS strategy. We suggest time c onstraints preclude the escalation of grooming bout length as required by R TS; the data were more consistent with a strategy of give as good as you ge t. However, this strategy could not explain all the patterns observed, and we conclude that biological market theory represents a more appropriate fra mework for investigating female grooming dynamics than dyadic games based o n the iterated prisoner's dilemma. We suggest that competitive altruism amo ng individuals acts as a-market force influencing an individual's value as a grooming partner. (C) 2000 The Association for the Study of Animal Behavi our.