Adolescent boys and girls were compared with middle-aged men and postmenopausal women on their performance on 3-dimensional space perception test. Results indicate that sex difference was evident only for the adolescent group and not for the middle-aged. Adolescent boys performed significantly better compared to girls. Age difference on spatial task performance was obtained only for males and not for females where postmenopausal women outperformed adolescent girls. Findings are explained in terms of progressive hemispheric lateralization and psychological differentiation across the life span.

Key words: spatial ability, sex differences, age differences, life span development, lateralization