Among the proliferation of research and writing on social movements during the past several decades, two of the major movement related topics covered by scholars are collective identity and the role of social movement organizations. By drawing from the organizational theory literature, we claim that in order to improve their survival chances, social movement organizations that belong to the first cohort of entrants in an emerging domain of mobilization and contention establish a tie with the identity of other organizations in related domains, after which they model their own identity. We also claim that these organizations will not be able to release themselves from this kinship, and that their identity changes over time will follow and will be constrained by the identity changes of their reference identity. We will test our theory by collecting evidence from an in-depth case study of the Italian gay and lesbian national organization between its foundation and 2007