Age and gender differences in smiling and laughter: the power asymmetry hypothesis retested

The power asymmetry hypothesis puts smiling and laughter into the context of relationships, in particular the inequalities between people within interactions. As a means of appeasement, junior members are expected to display higher than usual rates of deliberately affiliative gestures towards senior (dominant) counterparts (compared to rates towards non-senior counterparts). Previous researchers found these effects for males but not females. In a new observational study, we compared rates of smiling and laughter within male-male and female-female dyads in bars and restaurants in London UK. Age was used as a proxy for social status (older presumed dominant). Individuals within these focal dyads were classified in two ways: sex, and estimated age (binary category using age thirty-five as a dividing line). Instances of smiling and laughter were classified as either deliberate or spontaneous. In total, 150 dyads were observed. Some power asymmetry effects were found for male-male but not female-female dyads. Younger males displayed higher rates of deliberate laughs towards older males and older males displayed more deliberate smiles towards other older males. Females displayed more affiliative behaviors when interacting with peers compared to older counterparts. These results partly replicate earlier studies and provide support for power symmetry effects amongst males only.