This study was designed to determine the developmental trends in the difference between right-hand and left-hand skill development in children ages 4 to 9 as measured by the Motor Accuracy Test-Revised (MAC-R). There were 120 right handers (60 males, 60 females), with 20 subjects at each age interval, and 68 left handers (36 males, 32 females), with no less than 8 and no more than 20 subjects at each age interval. Performance was analyzed by sex, age, and handedness for the difference scores between the two hands, and the preferred and nonpreferred hand adjusted scores.
The difference scores were obtained by subtracting the nonpreferred hand scores from the preferred hand scores. Results showed the mean difference between hands for all children to be 6.7 points with a standard deviation of 4.8. This data suggests that a normative range of difference between right-hand and left-hand skill performance on the MAC-R may be from 2 to 11 points.
Left-handed children performed very similarly to right-handed children, supporting the use of right-handed norms for left-handed subjects. No significant differences in sex or handedness were found in the adjusted or difference scores. Comparison of the means and standard deviations of MAC-R normative data with these data showed no consistent significant differences.