Individuals define themselves, at times, as who they are (e.g., a psychologist) and, at other times, as who they are not (e.g., not an economist). Drawing on social identity, optimal distinctiveness, and balance theories, four studies examined the nature of negational identity relative to affirmational identity. One study explored the conditions that increase negational identification and found that activating the need for distinctiveness increased the accessibility of negational identities. Three additional studies revealed that negational categorization increased outgroup derogation relative to affirmational categorization and the authors argue that this effect is at least partially due to a focus on contrasting the self from the outgroup under negational categorization. Consistent with this argument, outgroup derogation following negational categorization was mitigated when connections to similar others were highlighted. By distinguishing negational identity from affirmational identity, a more complete picture of collective identity and intergroup behavior can start to emerge.