Fernández-Dols, J.-M., &Ruiz-Belda, M.-A. (1995). Are smiles a sign of happiness? Gold medal winners at the Olympic Games. Journal of Personality and Social Psychology, 69(6), 1113-1119.

All facial behavior displayed by 22 Olympic gold medalists during their awards ceremonies was codified. The awards ceremony contains one stage in which the medalist interacts with others and two noninteractive stages. Observers (including 10 other gold medalists) judged the emotional experience of the gold medalists to be intense happiness throughout the ceremony. However, smiles were frequent only during the interactive stage. As predicted by behavioral ecological theories of facial behavior, happiness was not sufficient for smiling.

 

 

http://dx.doi.org/10.1037/0022-3514.69.6.1113