Competition-related factors directly influence preferences for facial cues of dominance in allies.

Abstract: Alliance formation is a critical dimension of social intelligence in political, social and biological systems. As some allies may provide greater "leverage" than others during social conflict, the cognitive architecture that supports alliance formation in humans may be shaped by recent experience, for example in light of the outcomes of violent or non-violent forms intrasexual competition. Here we used experimental priming techniques to explore this issue. Consistent with our predictions, while men's preferences for dominant allies following losses (compared to victories) in violent intrasexual contests, women's preferences for dominant allies following losses (compared to victories) in violent intrasexual contests. Our findings suggest that while men may prefer dominant (i.e. masculine) allies following losses in violent confrontation in order to facilitate successful resource competition, women may "tend and befriend" following this scenario and seek support from prosocial (i.e. feminine) allies and/or avoid the potential costs of dominant allies as long-term social partners. Moreover, they demonstrate facultative responses to signals related to dominance in allies, which may shape sex differences in sociality in light of recent experience and suggest that intrasexual selection has shaped social intelligence in humans.

Significance Statement: Although alliance formation is an important facet of social intelligence in political and biological systems, we know relatively little about the cognitive processes involved in social preferences for allies. As recent experience may alter the leverage provided by different social partners, here we tested whether preferences for facial cues to dominance-prosociality (masculinity-femininity) alter in light of recent experience of violent and economic contests for status. Our findings demonstrate sex-specific responses to these facial cues. While men's preferences for facial cues related to dominance in allies following losses (compared to wins) in violent contests, women's preferences for facial cues related to dominance in allies following losses (compared to wins) in violent contests. These findings suggest that intrasexual selection, in part, has shaped the evolution of social intelligence in humans as revealed in flexibility in social preferences for allies.