EXPRESS: The Collective Identity Effect: How Group-Level Identity Influences Individual Behavior

This study investigates group-level customer–company identification (CCI), extending social identity theory to explore how individual-level identification evolves into strong, collective group dynamics. By analyzing interconnected customer groups, the research demonstrates how these dynamics shape individual behavior and drive organizational outcomes across diverse group types. Drawing on a comprehensive, three-year data set from a national retailer, the study assesses collective CCI within these groups. The findings reveal that group-level CCI significantly influences individual CCI, which in turn affects consumer spending and share of wallet. Furthermore, the research identifies the optimal conditions for maximizing group influence, highlighting that moderately sized (10-20 members), homogenous groups that meet three to ten times per year have the greatest impact. These insights enhance the understanding of CCI by focusing on group-level effects and extending social identity theory to address the conditions under which group-level identification exerts the strongest influence. The study offers practical strategies for managers to build group cohesion, foster loyalty, and improve customer interactions by leveraging group dynamics across organizational, social, and consumer contexts.