The Relationship between General Ability Using the Naglieri Nonverbal Ability Test (NNAT) and Stanford Achievement Test (SAT) Reading Achievement

The relationship between ability measured nonverbally and reading achievement was assessed to determine whether there were developmental differences in the correlations between the variables and to determine the size of the coefficient. It was previously suggested that the relationship between reading and intelligence is not a strong one and that the correlations change considerably across the K through 12th-grade interval. The present study involved approximately 22,000 children who were administered a nonverbal measure of ability called the Naglieri Nonverbal Ability Test (NNAT) and measures of reading included in the Stanford Achievement Test Ninth Edition (SAT-9). Results demonstrated that the NNAT was strongly correlated with the SAT-9 and that the overall correlation with Total Reading was large (.56). The hypothesis that ability and reading correlations change considerably across grades K-12 was not supported, but the view that intelligence as measured by a nonverbal test and reading are strongly related was supported.