Personality disorders and the interpersonal octagon.

The interpersonal octagon is a theoretical structure, similar to the interpersonal circle, within which a person's relating tendencies can be defined. It is constructed around a horizontal axis, concerning relating either closely or distantly, and a vertical one, concerning relating either downwardly or upwardly. The Person's Relating to Others Questionnaire--Revised Version (PROQ2) was designed to measure relating within the octagon. To test the validity of the proposed location of the 10 DSM-IV personality disorders within the octagon, the PROQ2 was administered, together with the DSM-IV version of the Personality Diagnostic Questionnaire (PDQ-IV), to a series of 107 men admitted to a therapeutic prison. The mean PROQ2 scores of the prisoners fell mid-way between those of male students and psychotherapy patients. High intercorrelations were found between the scale scores of both the PROQ2 and the PDQ, and there was a high correlation between total scores of the two instruments. All disorders were highly correlated with the lower close scale of the PROQ2. The locations of some disorders corresponded well with the pre-study predictions, and those of others came close. Those of a few came far from what was predicted, and some explanations for this are offered.