Developmental correlates of handedness in a national sample of 11-year-olds.

Some developmental correlates of hand preference in a large nationally representative sample of 11-year-old schoolchildren were examined. Non-right handedness was found to have slight, but statistically significant, associations with deficits of performance on certain standardized attainment and ability tests; with "poor speech" as assessed impressionistically by teachers in school; and with "poor control of hands" as similarly assessed by teachers. Non-right handedness was not associated with defects of articulation or stammering as assessed by doctors in a medical examination; nor withperformance on a clinical speech test; nor with writing productivity or syntactic maturity. There were substantial sex differences in the frequencies of non-right handedness, but no social class differences.