Intelligence, learning and long-term memory

In an influential paper Woodrow (1946) concluded that the ability to learn, which he defined as the gain over practice from initial performance, is not related to intelligence and that there is no unitary general learning ability. Ackerman (1989a) concluded that the initial stages of skill learning are related to intelligence, but later stages depend on speed factors. Previous studies often involved a substantial procedural memory component. This study is concerned with acquisition to long-term episodic memory and its relation to intelligence. A battery of verbal and visuospatial measures of learning, memory and abilities were administered to 45 subjects aged 17–25 yr. On multi-trial learning tasks the number of unrecalled items presented for learning after Trial 1 was controlled by an adaptive learning procedure. Total verbal and non-verbal memory performance was significantly correlated with total verbal and visuospatial ability (r = 0.48). The correlation of verbal memory with verbal ability was significantly higher than with spatial ability, suggesting that modality may contribute to individual differences in memory. For memory tasks with multiple trials, the improvement in performance over trials, indicating the rate of learning or gain, is also significantly correlated with cognitive ability (r = 0.44). Learning gain correlates 0.74 with first trial memory acquisition, which correlates 0.42 with ability. If learning is defined as the gain of new verbal and non-verbal information to long-term memory, then this study found that this is strongly related to initial acquisition to memory, and both are moderately related to intelligence.