Smiles of Affiliation and Dominance when competing for Leadership: The effect of gender in the 2016 US Presidential Debates

For human observers’ slight differences in the muscular configurations of the smile can communicate dominance or affiliation. Despite the significant role played by smiles, our gender modulates their valance. Females tend to smile more than men and are judged more negatively if they smile less than their male counterparts. Given that the smile is associated with effective leadership it remains to be seen whether or not gender moderates such displays during leadership campaigns. To examine this question the non-verbal displays occurring in the 2016 US presidential debate were analysed in a unique video case-study approach. Specifically, it was hypothesised that the female politician (Hillary Clinton) would engender more smiles in general and displays of affiliation specifically. Given the rehearsed, yet unpredictable, nature of such debates it was further hypothesized that the displays would be more intense when each candidate watched the other respond not when they responded directly. Differences in smiles of affiliation and dominance were analysed and results did indeed support the hypothesis that the more intense displays were engendered by candidates when watching their counterpart respond to the moderator. The female politician made more intense smile displays in general and more affiliative smile gestures specifically than the male politician (Donald Trump). These results are discussed in terms of the sociobiological significance that such honest social signals may have in a contemporary political campaign. As is common practice limitations and proposals for future work are discussed.