Abstract
Previous studies have suggested that the expression of smiles while viewing an emotionally loaded stimulus is facilitated by the presence of friends. This effect seems to be mediated by communication motives. If smiles had a communicative function, a person in front of friends would smile not only during the stimulus presentation period but also after it. In the current study, pairs of friends or strangers were videotaped during and after they viewed film clips, which were expected to elicit positive or negative affects; the control group did not have partners. We measured the duration and the frequency of smiles, frowning, and looking at their partners. Smiles were facilitated by the presence of a friend rather than that of a stranger or than being alone. In the post stimulus presentation period, pairs of friends and strangers smiled a lot, but not lone participants. Gazing also occurred during the post stimulus presentation period. These results suggested that the expression of smiles and gazing could be classified as affiliation behavior with partners.
