On the myth and the reality of the temporal validity degradation of general mental ability test scores

Abstract

Claims of changes in the validity coefficients associated with general mental ability (GMA) tests due to the passage of time (i.e., temporal validity degradation) have been the focus of an on-going debate in applied psychology. To evaluate whether and, if so, under what conditions this degradation may occur, we integrate evidence from multiple sub-disciplines of psychology. The temporal stability of construct validity is considered in light of the evidence regarding the differential stability of g and the invariance of measurement properties of GMA tests over the adult life-span. The temporal stability of criterion-related validity is considered in light of evidence from long-term predictive validity studies in educational and occupational realms. The evidence gained from this broad-ranging review suggests that temporal degradation of the construct- and criterion-related validity of ability test scores may not be as ubiquitous as some have previously concluded. Rather, it appears that both construct and criterion-related validity coefficients are reasonably robust over time and that any apparent degradation of criterion-related validity coefficients has more to do with changes in the determinants of task performance and changes in the nature of the criterion domain rather temporal degradation per se (i.e., the age of the test scores). A key exception to the conclusion that temporal validity degradation is more myth than reality concerns decision validity. Although the evidence is sparse, it is likely that the utility of a given GMA test score for making diagnostic decisions about an individual deteriorates over time. Importantly, we also note several areas in need of additional and more rigorous research before strong conclusions can be supported.