Calendrical calculation and intelligence

Naming the days of the week for dates in the past and future is a rare tale nt observed in people with low measured intelligence. The talent and other savant skills are more common in the autistic population, suggesting featur es of autistic cognition such as obsessive preoccupation and weak central c oherence may facilitate development of savant skills. This study describes the date calculation skills and performance on other calendar tasks by 10 c alendrical savants whose WAIS IQs range from 50 to 97. Their Block Design s cores were unexceptional, contrary to the weak central coherence explanatio n. Accuracy in date calculation and knowledge of calendrical regularities c orrelated with full scale IQ, indicating that the talent depends on intelli gence. Accuracy, range and latency of date calculation and latency for othe r calendrical tasks showed marked associations with Digit Symbol subscale s cores.