A large body of research has pointed to the utility of individual and group goal setting as a performance enhancement strategy. However, group goal setting is more complex than individual goal setting as the group context often strengthens the desire for voice and the possibility of resistance. In line with this idea, we test the prediction that goal-related performance improvements should be more marked where groups participate in goal setting rather than having goals imposed—particularly as they become increasingly hard to achieve. These ideas are tested in two experiments (Ngroups = 27, 72). Both confirm the capacity for group goal setting to enhance brainstorming performance. More importantly, both studies also show that the benefits of participative goals relative to imposed goals becomes more marked as goals become more difficult over time. In line with social identity and self-categorization principles, we suggest that this is because increases in participatively set goals appear to provide opportunities for collective self-actualization and self-enhancement while increases in imposed goals do not. Copyright © 2008 John Wiley & Sons, Ltd.