Lateral Dominance, Lateral Awareness, and Reading Disability

Lateral preferences for hand and eye and awareness of right-left relations were studied in an age-homogeneous sample of 200 boys selected from the total population of 9- and 10-year-old boys attending school in Aberdeen, Scotland. One hundred and fifty boys represented the poorest readers selected on the basis of four reading tests. The remaining 50 boys were controls matched for birth date and school placement and were drawn from the remaining readers. There were no differences in the lateralization of preferential hand and eye usage between the two groups. Significant differences were found in the level of right-left orientation. Confusion in right-left identification of own body parts in retarded readers was associated with the lowest scores on tests of sequential reading. Analysis of intellectual performance in the retarded readers indicated that disturbance in lateralization was more strongly associated with performance than with verbal IQ. The developmental course of the functions is considered, and the findings are compared with those found among samples in which selection biases may have occurred.