The affective component of group cohesiveness is reconceptualized in terms of a distinct group‐based form of attraction: social attraction. It is hypothesized, from self‐categorization theory, that under conditions of self‐conception based on social as opposed to personal identity the basis and structure of attraction within a group becomes depersonalized in terms of the group prototype. Four‐person single‐sex groups made autokinetic judgements under conditions designed to accentuate individuality (low salience) or group membership (high salience). Females behaved as predicted. They manifested depersonalized attraction associated with self‐categorization in group terms, indicated by greater convergence on the group norm in the high salience condition. For males depersonalized attraction occurred in the low salience condition and was linked to convergence on some, not all, measures. The results are discussed in terms of subjective uncertainty, which was abnormally and inexplicably high among low salience male groups, and differences between this and an earlier naturalistic study by Hogg&Hardie (1991). In the light of this discussion it is concluded that the data for both sexes conform to a self‐categorization analysis of soci