Sensory discrimination as related to general intelligence

Abstract

The hypothesis, originally proposed by Galton and elaborated by Spearman, that there is a functional correspondence between sensory discrimination and general intelligence ( g) continues to spark debate. Previous findings suggest that pitch discrimination and tactile discrimination are only weakly correlated with g. This study sought to replicate the pitch discrimination findings and to expand them to the modality of color discrimination in a large sample ( N=899) by correlating two sensory discrimination measures with the general factor from a battery of 13 cognitive-ability tests. The modest correlations found between g and measures of pitch discrimination ( r=.21) and color discrimination ( r=.31) suggest that sensory discrimination is relatively distinct from general intelligence. Although consistent with the neural processing speed explanation of g, these results cast doubt on a strong form of the sensory discrimination explanation of g.