License or obligation to smile: The effect of power and sex on amount and type of smiling

This experiment tested whether social power and sex affect amount and type of smiling. Participants were assigned to low-, high-, or equal-power positions and interacted in dyads. For high- and equal-power participants, smiling correlated with positive affect, whereas for low- power participants, it did not. Women smiled more than men overall and showed more Duchenne smiling in the equal-power context, but they did not differ in the high-power context or low-power context. Results are interpreted as reflecting the license given to high-power people to smile when they are so inclined and the obligation for low-power people to smile regardless of how positive they feel.