Where and why g matters:: Not a mystery

g is a highly general capability for processing complex information of any type. This explains its great value in predicting job performance. Complexity is the major distinction among jobs, which explains why g is more important further up the occupational hierarchy. The predictive validities of g are moderated by the criteria and other predictors considered in selection research, but the resulting gradients of g's effects are systematic. The pattern provides personnel psychologists a road map for how to design better selection batteries. Despite much literature on the meaning and impact of g, there nonetheless remains an aura of mystery about where and why g cognitive tests might be useful in selection. The aura of mystery encourages false beliefs and false hopes about how we might reduce disparate impact in employee selection. It is also used to justify new testing techniques whose major effect, witting or not, is to reduce the validity of selection in the service of racial goals.