Dog-Human Coevolution: Cross-Cultural Analysis Of Multiple Hypotheses

Dogs' relationship with humans is pervasive and familiar, and human-dog social bonds serve multiple functions. Yet the breadth and depth of this variation is poorly understood. This study considers our coevolutionary relationship in cross-cultural context as a self-organizing system of mutual-attraction between complementary species. We analyzed Human Relations Area Files (FIRM) texts to develop three scales of dog-human relationships: dogs' utility for humans (DUI-4), humans' utility for dogs (HUD), and personhood of dogs (PD). Using multilevel regression analyses of data from 844 ethnographers in 144 cultures, we evaluated multiple hypotheses for dog-human coevolution, including: influence of ecological constraints (temperature and pathogen stress), subsistence systems (hunting-agriculture continuum, livestock production), resource defense (intergroup violence, crime), and gendered-relationships (dog affiliation with men and women). Ambient temperature and pathogens showed the strongest and most consistent effects on DUH, HUD, and PD. Mutual-utility and dog-personhood increased as temperature decreased. Rithogens showed non-linear effects: outcomes increased with pathogens up to moderate-high levels, then decreased at higher levels, suggesting zoonotic infection risk. DUH, HUD, and PD were positively associated with hunting and negatively associated with food production. Intergroup violence was positively associated with dog-personhood, but not mutual-utility. Affiliation with adults was positively associated with all three outcomes; however, women showed a significantly stronger effect than men on HUD and personhood. We place these quantitative results in ethnographic context. Together these data suggest dog-human coevolution was constrained by ecological factors, enhanced by cooperative hunting and resource defense, and disproportionately influenced by dogs' relationships with women.