Differences between Caucasians and American Indians on the cognitive laterality battery

Caucasians scored significantly better than American Indian college students on verbal-sequential tests, but not on visuospatial tests, of Gordon's Cognitive Laterality Battery (CLB). Caucasians scored more right-biased than American Indians on the Edinburgh Handedness Inventory (EHI). The effects of percentage of Native American ancestry, strategy employed to recall serial sounds, bilingualism, familial sinistrality and handedness laterality on test performance were also analyzed. Results are consistent with hypotheses drawn from Annett's genetic theory of human laterality, if frequency distributions for the hypothesized rs+ gene are assumed to vary across the parent populations from which the samples were drawn.