Validation of the Frey and Detterman (2004) IQ prediction equations using the Reynolds Intellectual Assessment Scales

This study sought to assess the ability of the equations Frey and Detterman (2004) presented to assess IQ in the Reynolds Intellectual Assessment Scales (RIAS). The study confirmed Frey and Detterman’s equation (2) best predicted IQ from recentered SAT scores. Nonetheless, both of the Frey and Detterman’s equations did not match the optimal model found in the current data, namely that SAT Total or SAT Verbal, alone, best predicted IQ as measured by the RIAS. Implications from this study are much the same as those stated by Frey and Detterman, namely, that SAT appears to be a measure of general intelligence and is a useful tool in predicting cognitive functioning. Nonetheless, future research is needed with a wider range of IQ instruments to assess which SAT variables are the best predictors, and what weight each should be ascribed.