In the present study, speeded tasks with differing assumed difficulties of the trials are regarded as a special class of simple cognitive tasks. Exploratory latent growth modeling with data-driven shape of a growth curve and nonlinear structured latent curve modeling with predetermined monotonically increasing functions were used to analyze…

The hypothesis that racial differences in IQ stem from differences in components of executive systems including knowledge base, control processes, and metacognition was investigated. Group differences in metamemory, strategy use, and general knowledge, but not perceptual efficiency, were observed. Metamemory predicted crystallized but not fluid…

Relationships between intelligence test scores and measures derived from reaction time and perceptual speed procedures were investigated. Only three reaction time measures produced correlations greater than .25 with a general intelligence factor. Test-retest reliability of reaction time measures was low. The reaction time-intelligence relationship…