Development and validation of the Self-Identity Inventory (SII): a multicultural identity development instrument

The Self-Identity Inventory (SII) was developed using the Optimal Theory Applied to Identity Development (OTAID) model. A sample of 325 culturally diverse respondents completed the SII, the Tolerance Scale from the California Psychological Inventory, the Belief Systems Analysis Scale, and the Social Desirability and Infrequency Scales. Through confirmatory factor analysis, goodness-of-fit, and social desirability/item infrequency measures, SII items were analyzed, resulting in a 6-scale, 71-item inventory. Internal consistency for the scales ranged from .72 to .90. Test-retest reliability ranged from .72 to .92. Correlations with external construct validity measures supported predictions. Interscale correlations and other statistical tests primarily supported the OTAID model. Implications for therapy and future research are suggested.