Psychometric intelligence correlates with reaction time in elementary cognitive tasks, as well as with performance in time discrimination and judgment tasks. It has remained unclear, however, to what extent these correlations are due to top-down mechanisms, such as attention, and bottom-up mechanisms, i.e. basic neural properties that influence…

Groups of retarded and nonretarded children were investigated as they learned three rules underlying problems adapted from the Raven Progressive Matrices Test: rotation, imposition, and subtraction. Results were seen as consistent with theories that emphasize transfer flexibility as one potential source of individual and comparative differences in…