Construction of Circumplex Scales for the Inventory of Interpersonal Problems

We constructed a set of circumplex scales for the Inventory of Interpersonal Problems (IIP; Horowitz, Rosenberg, Baer, Ureno, & Villasenor, 1988). Initial scale construction used all 127 items from this instrument in two samples of university undergraduates (n = 197; n = 273). Cross-sample stability of item locations plotted against the first two principal components was high. A final set of eight 8-item circumplex scales was derived from the combined sample (n = 470) and cross-validated in a third university sample (n = 974). Finally, we examined the structural convergence of the IIP circumplex scales with an established measure of interpersonal dispositions, the Revised Interpersonal Adjective Scales (IAS-R; Wiggins, Trapnell, & Phillips, 1988). Although both circumplex instruments were derived independently, they shared a common circular space. Implications of these results are discussed with reference to current research methods for the study of interpersonal behavior.