Abstract
The objective of this paper, in line with the other papers of this special issue, is to show the potentialities of combining intelligence research and cognitive psychology. The development of intelligence is here addressed from two usually separate perspectives, a psychometric one, and a neo-Piagetian one. Two studies are presented. In Experiment 1, children aged 6, 7, 9, and 11 years (N = 100) were administered two working memory tasks and three Piagetian tasks. In Experiment 2, children aged 8–12 years (N = 207), young adults aged 20–35 (N = 160), and older adults aged 60–88 years (N = 135) were administered working memory and processing speed tasks, as well as the Raven Standard Matrices task. Regression and commonality analyses were run to analyse the age-related variance in the Piagetian tasks (Study 1), and in the Raven task (Study 2). In both experiments, working memory accounted for a large part of the age differences observed, but more so in Study 1 (Piagetian tasks) than in Study 2 (Raven task). It is concluded that working memory mediates the effect of age on fluid intelligence during childhood and during adulthood.