North American adult reading test: Age norms, reliability, and validity

The North American Adult Reading Test (NAART) is a quickly administered index that is widely used to estimate verbal intellectual ability. We have administered NAART to 351 healthy adults between 18 to 91 years of age to examine psychometric properties of the NAART and to elucidate influence of age, education and gender on NAART performance. The results showed that the NAART is a reliable and valid measure of verbal intelligence, comparable in psychometric properties to the WAIS-R Vocabulary test and with equal psychometric properties in young, middle-aged and older adults. The NAART scores increase across the adult life span (similar to4.5 points or similar to0.5 SD) and with education (similar to1.5 points/year of education) but they are unrelated to gender. The shorter version-the NAART35-is equally reliable and valid in predicting the WAIS-R Vocabulary. We provide norms as well as various equations for precise predictions of the NAART, the NAART35, and the WAIS-R Vocabulary scores based on age and education. Hierarchical regression analyses demonstrated that the verbal intelligence indexes are useful in predicting and interpreting performance on at least some, but not necessarily all neuropsychological tests, in addition to participants' age.