Administered five Piagetian tests to 180 adolescents for comparison to similar samples from 1967 and 1972. Found that today's adolescents exhibited higher levels of cognitive development than did previous cohorts. Gain varied across tasks, being very large for combinatory thought but mixed for conservation. This acceleration of cognitive…

This study contributes to the debate about the Flynn effect by proposing a long-term comparison (1921-2001) of the numerical knowledge of two cohorts of three- to five-and-a-half year-old children. In 1921, Beckmann (1923) assessed the numerical development of children using four tasks (Production, Distinction, Recognition, and Naming). In 2001,…