Original Adult MMPI Norms in Normal Samples: A Review With Implications for Future Developments

Among the most consistent criticisms of the Minnesota Multiphasic Personality inventory (MMPI) has been the adequacy of the standardly employed adult norms. Recent work at the Mayo Foundation has provided revised adult norms, and the Restandardization Project at the University of Minnesota Press will soon provide an additional norm set. This article reviews findings from 21 studies of normal adults, comparing obtained MMPI scale values to the standard norms. These comparisons indicate that the traditional adult norms may have contained detectable degrees of bias since their publication, and that consistent patterns of differences from standard MMPI norms can be found in independent studies published as early as 1949. Two separate considerations impact on the development of new adult norms: the research need for adult norms which accurately reflect the response patterns of the general population and the clinical need to evaluate individual psychiatric patients on norms that produce codetypes related to an empirical literature spanning more than 40 years. This study notes the inherent tension between these two purposes and discusses the implications of new adult MMPI norms for research and clinical practice.