This study puts forth the hypothesis that individuals become criminals because of the presence of a persistent criminal identity which has its origin in processes of negative social comparisons carried out by individuals who have failed in their pro-social roles and have exhibited non-conforming behaviour, aggravated and compounded by contextual factors (e.g. dysfunctional family environment, criminal peers). It is also suggested that development of a criminal identity might be influenced by representations of known criminals which are stored in memory system, and are made accessible due to relevant situational cues. This is consistent with the concept of multiple social identities which postulates that as a person’s social context changes, corresponding social identity changes are likely to occur as a result of the activation of situation-specific schemas. Importantly, this paper also introduces the notion that personality could potentially mediate the relationship between the social context and the subsequent development of Criminal Social Identity.