Social and emotional messages of smiling: An ethological approach.

Did smiling evolve as an expression of happiness, friendliness, or both? Naturalistic observation at a bowling alley (N — 1,793 balls) shows that bowlers often smile when socially engaged, looking at and talking to others, but not necessarily after scoring a spare or a strike. In a second study, bowlers (N =166 balls) rarely smiled while facing the pins but often smiled when facing their friends. At a hockey game, fans (N = 3,726 faces) smiled both when they were socially involved and after events favorable to their team. Pedestrians (TV = 663) were much more likely to smile when talking but only slightly more likely to smile in response to nice weather than to unpleasant weather. These four studies suggest a strong and robust association of smiling with a social motivation and an erratic association with emotional experience.