ABSTRACT
Fluid reasoning (FR) is the capacity to think logically and solve problems in novel situations, independent of acquired knowledge. This chapter investigates the age-related trajectories of FR using a cohort-sequential sample spanning childhood and adolescence. The goal was to characterize the changes in FR from childhood to adolescence, as well as identify potential developmental mechanisms underlying such changes. Identifying the precise form that characterizes the changes in FR is important to obtain a formal description of its development. Practice-related effects would be expected to dominate at shorter delays between assessments. The magnitude of improvement between occasions decreased with age, supporting the idea that the most rapid improvements in fluid reasoning take place during childhood. No differences in such improvements were perceptible between males and females. To examine changes in fluid reasoning across age, a latent change score model was specified using age bins spanning from childhood through adolescence.
