Intellectual engagement (IE) refers to enjoyment of intellectual activities and is proposed as causal for knowledge acquisition. The role of IE for cognitive development was examined utilizing 2-year longitudinal data from 112 ninth graders (average baseline age: 14.7 years). Higher baseline IE predicted higher baseline crystallized ability but…

The essay integrates the psychometric intelligence approach with the cognitive-developmental approach or the stage theory erected by Piaget and his disciples. The latter led to Piagetian Cross-Cultural Psychology and the accumulation of an immense body of data. It shows that different IQ levels are indicative of the peculiar stages of cognitive…

This study investigates the relationships of domain-general cognitive abilities and domain-specific verbal and mathematical abilities to students' educational characteristics when two theoretically grounded, but competing structural models are applied. In the standard model, a single latent ability causes interindividual differences in the…