Arithmetic and aging: Impact of quantitative knowledge and processing speed

The main objective of this study was to examine how quantitative knowledge (Gq in the CHC model) and processing speed (Gs in the CHC model) affect scores on the WAIS-III Arithmetic Subtest (Wechsler, 2000) with aging. Two age groups were compared: 30 young adults and 25 elderly adults. For both age groups, Gq was an important predictor of Arithmetic score variance (R² = 48% and R² = 45%, respectively). However, in line with Salthouse, the results showed that processing speed predicted Arithmetic scores only for the older adults, not for the younger ones (additional 9% of the variance for the elderly vs. 1% of the variance for the young adults). These results can clarify the ambiguous evolution of Arithmetic scores with aging: Arithmetic performance with aging seems to follow an intermediate path between Gc and Gf. This suggests that both Gq and Gs have an impact on Arithmetic in aging.