Exchanging grooming, but not tolerance and aggression in common marmosets (Callithrix jacchus).

In this study, we investigated the reciprocal exchanges of grooming, tolerance and reduced aggression in common marmosets (Callithrix jacchus), a cooperatively breeding primate whose groups are typically characterized by uniformly high genetic relatedness and high interdependency between group members. Both partner control and partner choice processes played a role in the reciprocal exchanges of grooming. In contrast, we did not find any evidence of reciprocity between grooming and tolerance over a preferred food source or between grooming and reduced aggression. Thus, reciprocity seems to play a variable role in the exchange of cooperative behaviors in marmosets.