Primate Kin Preferences: Explaining Diversity

Kinship has long been recognized as one of the major organizing principles of primate social organization. However, kin preferences are not ubiquitous, and vary widely between and within species. They are constrained by factors that determine the kinship structure of groups, mechanisms available for recognizing kin, and the availability and/or distribution of limiting resources. Within groups, kinship also interacts with sex, rank, and age. Enduring mother-offspring bonds serve as important building blocks of matrilineal kin relationships in many species, but they are not inevitable even when mothers and adult offspring coreside. Patrilineal kin preferences are just beginning to be examined in a variety of species, and mechanisms have yet to be identified. The question of kin selection as an explanation for kin preferences continues to pose challenges. Recent studies support the operation of kin selection, but suggest that its limits may be narrow, rarely going beyond parent-offspring and sibling relationships.