Humans intranasally administered the neuropeptide oxytocin waste less and earn more spoils during intergroup conflict because oxytocin enables group members to better coordinate strategic attacking of out-groups.

Intergroup conflict increases human endogenous oxytocin, which predicts the medial prefrontal activity associated with ingroup pain and propensity to seek revenge upon the outgroup.

Outgroup conflict can negatively impact general reproductive behaviour, egg investment, and parental care, resulting in decreased reproductive output even in the absence of physical confrontations.

After experimentally simulated within-group conflict, dwarf mongoose bystanders engage in post-conflict management behaviour with a temporal delay.

A detailed discussion of the broad range of immediate, delayed, cumulative, and third-party fitness consequences arising from outgroup conflict showcases the importance of this neglected aspect of sociality as a powerful and widespread evolutionary force.

High-resolution GPS data revealed a quadratic relationship between group size and movement, with vulturine guineafowl groups of intermediate size exhibiting the largest home-range size and greater variation in site use.

How the body and brain respond to a gentle stroke dynamically changes depending on how familiar someone is with the other person.

While men’s mating success is predicted both by their strength/muscularity, voice pitch, height, and testosterone levels, their reproductive output is only predicted by strength/muscularity.