[Examining the reliability and validity of a Japanese version of the 12-item Erikson Psychosocial Stage Inventory (the 5th stage)].

This study aimed to develop a 12-item version of the Erikson Psychosocial Stage Inventory (the 5th stage) (EPSI (5th)) and examine its reliability and validity. University students (N = 545) participated in this study. Confirmatory factor analyses revealed that a two-factor model provided a better fit than alternative one-factor models. An analysis of Cronbach's α coefficients and the test-retest method showed acceptable scale reliability. In accordance with our hypotheses, correlation analyses revealed that the EPSI (5th) subscale scores (i.e., synthesis and confusion) were significantly related to measures of self-esteem, life satisfaction with life, and identity confusion. Implications and suggestions for future research are discussed.