This research examined favouritism in group product evaluations as a function of personal involvement. After being divided into groups on an arbitrary basis, subjects worked at a group brainstorming task. Some subjects then assessed the merits of their own group's product relative to that of an outgroup's product, whereas other subjects assessed the merits of an ingroup's product relative to that of an outgroup's product. In both conditions, a significant bias was observed such that owngroup and ingroup products were rated as superior to outgroup products. Moreover, this bias was equally strong regardless of whether subjects were appraising a product they had personally helped create. The implications of the findings for understanding the antecedents of group bias are considered.