Sixty preschool children (31 boys, 29 girls, 5-6 years old), 60 young adults (30 men, 30 women, 20-45 years old), and 66 older adults (23 men, 43 women, 60-94 years old), bisected 11 lines of different lengths, 1 time with each hand. All participants were French and right-handed. In all age and sex groups the mean transection was at the left of the true center regardless of the hand used. Accuracy of the left hand was better than accuracy of the right hand in children, but the opposite pattern was observed in older participants (better right hand), and there were no between-hands differences in accuracy among young adults. The observed patterns of correlation between the left and the right hand, which were age and sex dependent, are presented. These results are discussed in relation to age-related changes in hemispheric interaction and to the need for additional research on the reliability,and extent of the "neglect" in normal individuals.
