Infant expectations and reaction time as predictors of childhood speed of processing and IQ.

A longitudinal study investigated the relation between infant expectations and reaction time (RT) and childhood IQ and RT. Measures of visual anticipation and visual RT were taken at 3.5 months and 4 years of age. In addition, manual RT and verbal and performance IQ were measured at 4 years of age. Infant visual RT correlated reliably with childhood visual RT, and infant performance correlated significantly with childhood IQ. Childhood performance also correlated with concurrent childhood IQ. Children were slower to initiate eye movements when a manual choice button press was required than when it was not required. This load effect decreased as IQ increased. Visual RT and manual RT in childhood correlated only marginally. These are the first data to suggest stability in RT between early infancy and childhood or predictability from infant RT and anticipation in the first half-year of life to childhood IQ.