Single tests,competing tasks and their relationship to the broad factors of intelligence

This paper presents the results of three studies in which scores obtained on single and competing tests were correlated with the composites representing fluid intelligence, crystallized intelligence, and the short-term acquisition and retrieval function. The results indicate that competing tasks have higher correlations with intelligence than single tests. Since in two studies of this paper no decrements in performance were observed on the competing as compared with the single task, the concept of limited central processing capacity cannot account for individual differences in performance of these cognitive tasks. It is suggested that the concept of efficient processing of information, perhaps efficient encoding, may be the basis for individual differences in cognitive abilities.