Lateral preference in six to nine year old children: Relationships to language lateralization and cognitive ability

Abstract

Lateral preferences in hand, foot, eye, and ear are known to undergo significant increases in dextrality sometime between six and 15 years of age. The study investigated the age range from six to nine for evidence of such changes and tested whether individual differences in lateral preference were related either to hemispheric specialization for language or to cognitive ability. Measures of lateral preference, dichotic listening, verbal reasoning, and school grades were obtained in 227 normally achieving children. Increased dextrality was found between eight and nine years in foot preference and in hand and foot congruency. Except for a weak relationship to handedness, age-invariant language lateralization was psychometrically independent of (1) lateral preference and (2) all cross-preference coordinations, i.e., hand-eye. Superior cognitive ability was found in right handed males with right ear and left eye preference but in right handed females with left ear and right eye preference. The results (1) demonstrate an important link between motor development and cognitive ability and (2) suggest cautiously that the linkage may be mediated by gender differences in the cortical organization of the output pathways controlling lateral head turn, handedness, and eye preference.