Ingroup Identification as the Inclusion of Ingroup in the Self

This article presents a basic conceptualization of ingroup identification as the degree to which the ingroup is included in the self and introduces the Inclusion of Ingroup in the Self (IIS) measure to reflect this conceptualization. Using responses from samples of women and ethnic minority groups, four studies demonstrate the utility of this conceptualization of ingroup identification and provide support for the IIS. Results from these studies establish construct validity, concurrent and discriminant validity, and high degrees of test-retest reliability for the IIS. Reaction time evidence also is provided, supporting the use of the IIS as a measure of ingroup identification. Particular strengths of this conceptualization of ingroup identification and potential uses for the IIS are discussed.