The aim of the present study is twofold. First, we tested the view that individuals who do not develop a typically strong behavioral
laterality are distributed differentially among the two genders across age. Second, we examined whether left handedness and mixed
handedness are associated with an elevated risk of some developmental or cognitive deficits. A special recruitment procedure
provided norms of the Rey-Osterrieth Complex Figure (ROCF) copy from large samples of left-handed (𝑁 = 420) and mixedhanded
(𝑁 = 72) compared to right-handed (𝑁 = 420) schoolchildren and adults (𝑁 = 545). This graphic task was considered as
reflective of the growth of visual-spatial skills and impairment at copying as a developmental risk. Subjects' hand preference was
assessed by the Edinburgh Handedness Inventory. Data analysis indicated that (1) the trend towards consistent right handedness
is sex related. Girls are clearly ahead of boys in this lateralization process, and boys are overrepresented in mixed-handed subjects.
The greater prevalence of mixed-handed boys compared to girls decreases with age. (2) Performance on drawing the ROCF varies
according to age and handedness groups.Mixed-handed subjects scoredworse in all age groups.The results are discussed in relation
to the hormonal-developmental, neuropathological, and learning theories of lateralization.