Many disciplines deal with identity, and, within each of these, there are complex and overlapping ways of understanding it. The three perspectives on identity we selected for the series, and hence the booksociocultural, discursive, and psychoanalytic-have interesting and contrasting things to say on how people relate to mathematics, focussing, respectively, on practices and participation, language and power, and the role of the unconscious. These theoretical perspectives are very broad, and the authors interpret them very differently. Here we offer only the briefest of orienting introductions. Sociocultural theories derive from psychology and anthropology (Holland, Lachicotte, Skinner, & Cain, 1998; Lave & Wenger, 1991; Wenger, 1998) and have been widely taken up in education (e.g., Bloomer & Hodkinson, 2000), including mathematics education (e.g., Boaler & Greeno, 2000). These approaches view identity as being co-constructed through participation in social practice and seek to understand the ‘cultural models’ agents use, and are positioned by, in their identity work. Discursive approaches view identity as the result of the subject’s interpellation into discourse, systems of knowledge, and practice which construct objects; this process is inseparable from relations of power (Foucault, 1980). These approaches are of growing importance within the fi eld of mathematics education (Lerman, 1998) as are psychoanalytic approaches (Evans, 2000) which defi ne identity in terms of an interaction between conscious and unconscious processes and underline the value of focusing on the role of emotional and relational factors (Britzman, 1998). There are many tensions between these approaches. For example, there is a tension between the discourse insistence that we should not look inside people for explanations and the psychoanalytic concern with unconscious processes such as anxiety, fantasy, and defensive strategies. It is precisely these tensions that we feel make bringing these very different perspectives together so productive for addressing our overarching question: What can a focus on identities and relationships bring to understanding issues of inclusion in and exclusion from mathematics?