ABSTRACT
This chapter focuses on the differential tradition. It outlines the concept of ability in the psychology of individual differences as latent dimensions or traits which can be used to rank order individuals. Several models of intelligence are outlined, emphasizing different aspects of intelligence, such as general intelligence and more specialized abilities. The commonly accepted Cattell-Horn-Carroll three-stratum model, postulating that the human mind is organized in three hierarchical levels (general intelligence, broad domains, and specific skills and processes) is outlined. Research aimed at bridging the experimental and the psychometric tradition is summarized and evaluated. This research examined how the processes specified in the cognitive tradition are related to general intelligence and the other abilities specified by psychometric psychology. It is concluded that, although all of these processes are related to psychometric abilities (more intelligent individuals can better focus mental processes on a goal, they can hold more information in mind, are more flexible shifting between and combining information, and are better able to make inferences), none is sufficient to fully explicate intelligence on its own. Modern answers are summarized and evaluated.
