title: Home range overlap as a driver of intelligence in primates.
abstract: Various socioecological factors have been suggested to influence cognitive capacity in primates, including challenges associated with foraging and dealing with the complexities of social life. Alexander [Alexander, 1989]. Evolution of the human psyche. In: Mellars P, Stringer C, editors. The human revolution: Behavioural and biological perspectives on the origins of modern humans. Princeton: Princeton University Press. p 455-513] proposed an integrative model for the evolution of human cognitive abilities and complex sociality that incorporates competition among coalitions of conspecifics (inter-group conflict) as a major selective pressure. However, one of the premises of this model, i.e., that when confronted with inter-group conflict selection should favor enhanced cognition, has remained empirically untested. Using a comparative approach on species data, I aimed to test the prediction that primate species (n = 104) that face greater inter-group conflict have higher cognitive abilities (indexed by endocranial volume). The degree of inter-group conflict/complexity was approximated via the variable home range overlap among groups. I found a significant relationship between home range overlap and endocranial volume, even after controlling for other predictor variables and covariates such as group size and body mass. I conclude that brain size evolution cannot be attributed exclusively to social factors such as group size, but likely reflects a variety of social and ecological determinants including inter-group conflict which poses cognitive demands on monitoring both the wider social milieu as well as spatial attributes of the habitat.
authors.affiliation: School of Anatomy, Physiology and Human Biology, The University of Western Australia, Western Australia, Australia.
authors.forename: Cyril C
authors.initials: CC
authors.lastname: Grueter
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D005075:Biological Evolution; D001921:Brain / Q000033:anatomy & histology*; D003071:Cognition; D003163:Competitive Behavior; D006702:Homing Behavior; D007360:Intelligence; D009929:Organ Size; D011323:Primates / Q000033:anatomy & histology* / Q000523:psychology
keywords: brain size; comparative analysis; home range overlap; primates