From good senses to good sense: A link between tactile information processing and intelligence

Since the 1970s there has been an reemerging interest in Galton's (1883) senses-intelligence hypothesis. The essence of this hypothesis is the conceptual link between fine-tuned sensory functioning and superior intellectual ability. Several studies have investigated the sensory-cognitive link within auditory and visual modalities. In this study, the intersystemic relationship between sensory and cognitive functioning was extended to the tactile modality by examining the associations between three measures of tactile information processing and intelligence in a heterogeneous sample of middle-aged adults (N = 179; age range = 30-51). Two of the three tactile tasks measured discrimination ability (i.e., roughness discrimination and part-whole matching), whereas the third task measured tactile pressure sensitivity. Results from a series of analyses indicate that sensory measures from the tactile modality are at least as highly correlated with intellectual ability (r = .18 to .33) as measures of auditory (r = .15) or visual (r = .20) acuity. All together, the three tactile measures accounted for 20.8% of the total variance in intelligence. The two tactile discrimination measures were found to be better predictors of intelligence than measures of simple sensory acuity.