Validity of the Inventory of Interpersonal Problems (IIP-64) for predicting assertiveness in role-play situations

The Inventory of Interpersonal Problems (IIP-64; Horowitz, Alden, Wiggins, & Pincus, 2000) is a self-report measure of maladaptive relationship behavior. Ninety-five adult female participants completed the IIP-64 and then interacted with a same-sex confederate in three diagnostic role plays, designed to evoke assertive responses. After each role play, both the participant and the confederate judged how assertive the participant had been, using two subscales from the Interpersonal Adjective Scales (IAS; Wiggins, 1995). The participants' general self-images, assessed with the IIP-64, were quite congruent with how they judged their own assertiveness in the role plays. But when role-play assertiveness was judged by the confederate, the match with the participants' general self-images was considerably lower. Our results indicate that self-reported interpersonal problems do not converge well with external judgments of interpersonal behavior.