To assess the inter-relationships between neuropsychological and cognitive/social abilities of the preschool children, a dichotic listening test, a verbal ability test, a picture drawing test, a handedness test, a perceptual ability test, and social development test were administered. Multiple regression analyses showed that 1) the verbal cognitive ability correlated with right-ear advantage, chronological age, picture drawing ability, and social development, and 2) the social development correlated with verbal cognitive ability but not with other abilities. These results suggest that both hemisphere specialization and collaboration of hemispheres are important factors for high level of verbal and social abilities.