A latent variable analysis of working memory capacity, short-term memory capacity, processing speed, and general fluid intelligence

Abstract

Significant relationships exist between general fluid intelligence and each of the following constructs: short-term memory capacity, working memory capacity (WMC), and processing speed. However, the interrelationship among all four constructs has not been investigated. Multiple measures of each of these constructs were obtained from 120 healthy young adults. Structural equation modeling was then performed to determine which construct served as the best predictor of general fluid intelligence. The results suggest that WMC, but not short-term memory capacity or processing speed, is a good predictor of general fluid intelligence in young adults. Possible mechanisms underlying the link between WMC and general fluid intelligence are discussed.