Here's looking at you: Finding allies through facial cues

Alliance formation refers to the tendency among people to team up in pursuit of a common goal. It is an important facet of social intelligence among humans and other species. Not much is known however about the cognitive processes that come into play when people choose allies within different social settings -- and whether 'minimal information', such as snap judgments made about someone based on how their face looks, is used in our assessments of suitable allies.

Watkins and Jones tested how people associate specific facial cues with suitability as an ally in the aftermath of specific social experiences. To find out if there are specific gender differences to this, the researchers analyzed the responses of 246 young adults who completed an online experiment. Participants were first asked to visualize themselves either winning or losing one of two situations: a physical fight or a contest for promotion with a same-sex rival. They were then shown 20 pairs of male and female faces. These photographs were manipulated using computer graphic methods so that each pair consisted of a masculine and a feminine version of the same individual. On each trial, participants had to choose who they judge to be the better ally from looking at their facial characteristics alone.

In general men preferred masculine men as allies, in contrast to women who did not prefer masculine or feminine-looking faces when judging men as possible allies. However, feminine-looking women were preferred as allies by both men and women. According to Watkins and Jones, these general social preferences may have an evolutionary basis. Alliances with dominant men might benefitted ancestral males when competing against rival groups and improved the social rank of the male who selected a dominant ally.

"Our results suggest that there are sex-specific responses to facial characteristics which are flexible and change in light of a recent experience of confrontation," says Watkins. While men's preferences for dominant-looking allies were stronger after a loss compared to a win in a violent confrontation with another male, women's preferences for dominant-looking allies were weaker after a loss compared to a win in a violent confrontation with another female.

"These findings suggest that intra-sexual selection, in part, has shaped the evolution of social intelligence in humans as revealed by flexibility in social preferences for allies," say Watkins and Jones.