When liking begets solidarity: An experiment on the role of interpersonal attraction in psychological group formation

Abstract

The role of interpersonal attraction in psychological group formation is discussed. For the social cohesion model attraction and group formation are isomorphic, while the social identity approach identifies self‐categorization as the mechanism of group formation. This paper examines the ‘social attraction hypothesis' (Hogg & Turner, 1985) that interpersonal attraction only leads to group formation if it generates an assumption of common category membership that engages a cognitive process of identification. This hypothesis is experimentally tested in a 2(categorization/no categorization) x 2(idiosyncratically likable‐dislikable others) x 2(positively/negatively distinctive in‐group) factorial design employing the ‘minimal group’ paradigm. As predicted, group formation was found to be a function of the social attractiveness (positive distinctiveness) rather than the personal attractiveness (idiosyncratic likableness) of the in‐group members, and categorization (irrespective of affective relations) also generated group behaviour. Complex interactions revealed the unpredicted finding that individuals spontaneously form a group when aggregated with positively distinctive likable others in the absence of an explicit categorization. Social identity readily provides an explanation in terms of perceptions of interpersonal similarities which are transformed into social similarity and thus cause identification. The results of the study strongly favour the social identity approach to group formation.