Nonlinguistic Knowledge, Hemispheric Laterality, and the Conservation of Inequality in Nonconserving Children

Nonconserving children may fail to conserve because of difficulties in verbally expressing nonlinguistic knowledge of equivalence relationships. This may be partly due to an inability of the right hemisphere, which mediates the performance of internal reversals and conservation, to communicate with the speaking left hemisphere because of the immaturity of the corpus callosum. This relationship presumably results in the asymmetrical activation of the left hemisphere when verbal responses are required. To assess the possibility that nonconservers have an awareness of the reversibility of these operations, three groups of nonconserving children (N = 42) were either asked which of two containers (one of which appeared to contain more liquid, but had previously been shown to contain less) had more in it, or which (pretending they were very thirsty and it was their favorite drink) they would prefer. To assess whether nonconservers respond primarily with left hemisphere activation, patterns of lateral eye movement in response to verbal-analytic or spatial-emotional stimuli were obtained in a fourth group (N = 37). Both hypotheses were supported.