Normal People in Clinical Practice: A General Factor of Personality in Biproportional Scaling and Its Practical Relevance

Abstract

To investigate the clinical relevance of absolute scaling in personality assessment, Hofstee and Ten Berge's (2004) biproportional scaling method was applied to 3 clinical samples and compared with relative scaling in traditional analyses. In the first sample, 80 psychotherapy clients provided self-reports as well as reports by 3 informants, resulting in 320 ratings of the Dutch short form of the MMPI (NVM). In the second sample, 96 psychotherapy clients provided self-reports and informant reports, resulting in 384 Five-Factor Personality Inventory (FFPI) ratings. In the third sample, 95 clients provided self-reports and informant reports, resulting in 380 ratings of the NEO Five-Factor Inventory (NEO–FFI). In Part I of the study, the personality structure based on biproportional scaling was examined by replicating Hofstee, Barelds, and Ten Berge (2006). In Part II, this personality structure as well as self-informant distances and self-informant likenesses were related to symptoms, personality pathology, and level of functioning. The results confirmed the presence of a general factor of personality in absolute scaling, which appears to reflect social fitness and the absence of severe psychopathology. This factor was significantly associated with fewer symptoms and better functioning in all 3 samples. The personality pathology results were only significant in the FFPI sample. Self-informant distance and self-informant likeness were primarily associated with symptoms. A relationship between poor social fitness and insecure early attachment was suggested in 3 case studies.

Acknowledgment

I am greatly indebted to Professor Willem K. B. Hofstee for patiently teaching me, among other things, the biproportional scaling method, as well as for his helpful comments on earlier versions of this article.