Within social psychology, group identification refers to a mental process that leads an individual to conceive of herself as a group member. This phenomenon has recently attracted a great deal of attention in the debate about shared agency. In this debate, group identification is appealing to many because it appears to explain important forms of intentionally shared actions in a cognitively unsophisticated way. This paper argues that, unless important issues about group identification are not illuminated, the heuristic function ascribed to (...) this notion for an understanding of shared agency remains dubious at best and unfulfilled at worst. This paper offers such a clarification by distinguishing and describing two different mental processes that constitute group identification: adoption of the group perspective and transformation in self-understanding. It is claimed that the latter process consists in the production of what Ruth Millikan labels “Pushmi-Pullyu representations” and that it is developmentally prior with respect to the ability of adopting the group perspective. (shrink)