OUTGROUP: Consequences of out-group conflict

The aim of this project is to determine the proximate and ultimate consequences of a fundamental but neglected aspect of sociality: out-group conflict. In a wide range of social species, from ants to humans, group members invest considerable defensive effort against individual intruders and rival groups. The lasting impacts of these conflicts with conspecifics are poorly understood. I will integrate empirical and theoretical approaches to uncover the effect of out-group conflict on: (i) individual behaviour, within-group interactions and group decision-making; (ii) steroid hormones that underlie stress, social behaviour and reproduction; (iii) variation in reproductive success arising from maternal investment and offspring care; and (iv) the evolution of societal structure, cooperation and punishment among group-mates, and weaponry and fortification.