- The task of the clinician in evaluating the possible role of psychological factors in patients' pain disability is a most difficult one. This task becomes even more arduous when confronted with unelevated MMPI profiles from patients in whom physical findings are minimal or absent. The current study employs a multivariate, quantitative taxonomic procedure to delineate homogeneous subgroupings of chronic pain patients who meet this criterion. Subsequent analysis of base rate data for subgroups across a broad range of pain-related variables provide an actuarial basis of assessment of psychological factors within this population. Results indicate that of five subtypes identified, only one group of patients, who comprise 9% of the total sample, are likely to be free of significant psychological components in their pain behavior. Implications for clinical interpretation and future research are discussed.