Null sex differences in general intelligence among elderly

The g factor is common to a wide set of cognitive abilities and it is usually considered the most important predictor of success both in academia and everyday life. The information provided by summary intelligence scores, such as IQ, may or may not involve the g factor. This must be explicitly tested. With this main purpose in mind here we analyzed the Italian standardization sample of the Wechsler Adult Intelligence Scale-Revised (WAIS-R) for aged individuals, which was administered to 1168 healthy older adults from 65 to 84 years (584 men and 584 women). Their mean education was equivalent to 6.0 years of formal schooling (SD = 3.6). The average sex difference in FSIQ was equivalent to 7 IQ points favouring men. However, Multi-Group Confirmatory Factor Analysis revealed a null average sex difference in g.