An Evaluation of Millon's Circular Model of Personality Disorders

Abstract

Millon's personality styles in both normal and abnormal test form were examined from the point of view of Guttman's circumplex. Data came from a diverse sample of psychiatric patients (N = 159) who completed the Millon Clinical Multiaxial Inventory-II (MCMI-II) and from college students (N = 841) who completed the Personality Adjective Check List (PACL), a measure of Millon's styles for use with normals. Principal components analyses were conducted to identify the first two dimensions in MCMI-II base rate (BR) scores, weighted and unweighted raw scores, and nonoverlapping scale scores. Similar analyses were made on such scores when acquiescence was partialled out. PACL scores were analyzed similarly. Ordering of scales from the MCMI-II and PACL on the first two principal components was comparable. MCMI-II scales formed a more complete circle than PACL scales, with best results coming from scores corrected for acquiescence. Although scale order followed Millon's predictions for the most part, a number of departures from theoretical expectations were noted. Millon's model appears to have promise as a circumplex, but changes are needed to take acquiescence into account and to reorder some of the scales.