Abstract The Male Warrior Hypothesis (MWH) establishes that men's psychology has been
shaped by inter-group competition to acquire and protect reproductive resources. In this …

Parochial altruism, defined as increased ingroup favoritism and heightened outgroup
hostility, is a widespread feature of human societies that affects altruistic cooperation and …

Higher testosterone levels have been positively related to a variety of social behaviors and
personality traits associated with intrasexual competition. The aim of this study was to …

The steroid hormone testosterone is widely associated with negative behavioral effects,
such as aggression or dominance. However, recent studies applying economic exchange …

Coalitions and alliances are core aspects of human behavior. All societies recognize
alliances among communities, usually based in part on kinship and marriage. Aggression …

A contribution to a special issue on Hormones and Human Competition. Previous research
and theory suggest testosterone is an important hormone for modulating aggression and self …

Why do some people confronted with a threat choose to fight, while others confronted with
the same threat choose to retreat? When challenges differ, the level of provocation can help …

Although androgens are widely studied in the context of aggression, androgenic influences
on prosocial behaviours have been less explored. We examined testosterone's (T) influence …

Intergroup conflict has been a persistent aspect of human societies since the emergence of
our species. Various researchers have proposed that competition between groups has acted …

Experimentally elevated testosterone (T) often leads to enhanced aggression, with
examples across many different species, including both males and females. Indeed, the …