A meta-analysis of sex differences in physical ability: Revised estimates and strategies for reducing differences in selection contexts

Abstract

Despite the wide use of physical ability tests for selection and placement decisions in physically demanding occupations, research has suggested that there are substantial male-female differences on the scores of such tests, contributing to adverse impact. In this study, we present updated, revised metaanalytic estimates of sex differences in physical abilities and test 3 moderators of these differences- selection system design, specificity of measurement, and training-in order to provide insight into possible methods of reducing sex differences on physical ability test scores. Findings revealed that males score substantially better on muscular strength and cardiovascular endurance tests but that there are no meaningful sex differences on movement quality tests. These estimates differ in several ways from past estimates. Results showed that sex differences are similar across selection systems that emphasize basic ability tests versus job simulations. Results also showed that sex differences are smaller for narrow dimensions of muscular strength and that there is substantial variance in the sex differences in muscular strength across different body regions. Finally, we found that training led to greater increases in performance for women than for men on both muscular strength and cardiovascular endurance tests. However, training reduced the male-female differences on muscular strengths tests only modestly and actually increased male-female differences on cardiovascular endurance. We discuss the implications of these findings for research on physical ability testing and adverse impact, as well as the practical implications of the results. © 2013 American Psychological Association.