Key points are not available for this paper at this time.
Direction and degree of handedness were assessed in children aged 3 to 9 years old, in transverse and longitudinal studies, using a 10‐item performance battery. Item analysis revealed a single underlying factor with a bimodal distribution. Direction of handedness appears to be more or less fixed by the age of 3. Degree of handedness increases at least over the range 3 to 7 years, and perhaps more slowly from 7 to 9. Degree of handedness increased more rapidly in left‐handers than in right‐handers. Degree of handedness showed no correlation with reading ability or general intelligence. The theoretical implications of these findings are discussed, and interpreted in terms of a hypothesis whereby degree of handedness is a phenomenon sui generis.
McManus et al. (Thu,) studied this question.