Explaining commitment toward the peer group: the role of group membership functions.

Previous research has clearly shown that peer-groups fulfil a variety of psychosocial functions for their members, and that the importance of these functions is differently underlined by different group typologies (Graziani, Rubini, & Palmonari, 2006). The present study aimed at analysing the relationship between the group membership functions and the behavioural outcomes of group belongingness in different types of adolescent peer-groups. In particular, we hypothesised that the group membership functions have a direct impact on the commitment behaviours toward the ingroup, and that this relation would be mediated by ingroup identification. 556 adolescents, members of sports, religious, political and informal groups, participated in the study by filling in a questionnaire, in which they were asked to rate the importance of eight group membership functions (self-esteem, self-insight and social understanding, ingroup cooperation, intergroup competition, intragroup social comparison, romantic involvement, amusement, and leadership), the degree of ingroup identification and the frequency of ingroup specific commitment behaviours, that is behaviours facilitating the ingroup life. The results showed that the commitment behaviours were influenced by different group membership functions, particularly by “ingroup cooperation” and “self-insight and social understanding”. Moreover, the pattern of the functions explaining the commitment behaviours varied in the different peer-groups considered. Finally, as hypothesised, in all group typologies the relationship between the group membership functions and the commitment behaviours was mediated by ingroup identification. These findings represent an interesting contribution in order to understand the links between adolescents and their groups and the behavioural consequences of identification with one’s own peer-group.