This paper explores the ways in which the concept of identity has been conceptualised and studied within science education. The Personality and Social Structure Perspective is used to examine the attention paid by researchers to three levels of identity analysis: "personality", "interaction" and "social structure". Tracing the development of science identity studies and the resulting body of literature reveals that most authors have focused their attention on aspects of identity related to individual agency to the exclusion of issues of social structure. This paper argues that this attention is related to the position of communities of practice as the dominant theoretical framework for identity studies and argues that researchers need to consider broader frameworks that encourage the integration of ideas at all three levels of analysis. Broadened methodological approaches, including mixed methods, are also advocated as a way to increase consideration of the level of social structure. (Contains 2 figures.)