A Psychometric Examination of Rasmussen's Ego Identity Scale

Rasmussen's Ego Identity Scale (EIS) was examined for internal consistency reliability and construct validity. In Study 1, 114 seventh and eleventh grade students were given the EIS, the Marlowe-Crowne social desirability scale, Simmons' Identity Achievement Scale, and Rest's Defining Issues Test of moral development. Although the EIS was significantly related to age, identity, and moral development, its strongest relationship was with social desirability. In Study 2, an item analysis of the Study 1 data and a reworking of the EIS to a 30-item scale reduced the association with social desirability while still maintaining high internal consistency. Study 3 was a replication of the internal consistency findings of Study 2 and an exploration of sex effects which became evident in Study 2. Implications for identity assessment are drawn.