The Impact Message Inventory-Circumplex (IMI-C): a replication study of its circumplex structure in a Dutch sample

The 56-items Impact Message Inventory-Circumplex (IMI-C) has been developed to describe the interpersonal styles of target persons in terms of the 2-dimensional interpersonal circle, divided in 8 subscales (octants). The IMI-C is based on the assumption that a target person's interpersonal styles can validly be measured by assessing the internal (cognitive and emotional) reactions of the IMI-C respondent (e.g., therapists), interacting with the target person (e.g., psychotherapy patients). This replication study tested the circumplexity of a computer-delivered Dutch IMI-C. The computer-delivered Dutch IMI-C approached circumplexity in a large clinical sample (N = 812) of psychotherapy and psychiatric patients, after removing 3 items from the Submissive octant scale. These 3 items clearly disturbed the IMI-C circumplex structure. It is concluded that, even with the inevitable problem of nested data, circumplexity was approached sufficiently to justify the interpretation of the IMI-C at the octant level, provided that the 3 troublesome Submissive items are removed from the calculations of octant scores. Our replication test of the Dutch IMI-C circumplexity might be an impetus for researchers in the United States to invest in the further validation of the original American version.