Previous research has suggested that behavioral differences between shy and not shy persons may be explained by differences in inhibition rather than differences in interpersonal skills. To investigate the behavior of high and low social anxiety subjects in both ambiguous social situations and in explicitly structured ones, three studies using college students were conducted. Significant group differences were expected in the ambiguous but not the structured situations, indicating the group differences to be best interpreted as a difference in inhibition. In study 1, high compared to low social anxiety subjects were nominated significantly less often by their fellow group members as having generated humorous remarks during a group discussion task. However, in two structured situations comprising study 2, high social anxiety subjects generated cartoon captions and a comedy monologue that were equivalent in rated humorousness to those created by the low social anxiety group. This same pattern of results occurred in study 3, which investigated the dominance behavior of subjects in both a typical, ambiguous social situation, and in a structured one in which they were told to be as assertive as possible. High social anxiety subjects were rated as significantly less dominant than the low social anxiety group in the typical situation, but no group differences resulted in the maximal or structured situation. The group differences in the ambiguous situations were interpreted as showing a deficit in ability to initiate behavior sequences and/or the existence of motivation to avoid becoming the object of public attention. (Author/JAC)