Article

Sex Differences in Left-Handedness: A Meta-Analysis of 144 Studies

Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom.
Psychological Bulletin (Impact Factor: 14.76). 10/2008; 134(5):677-99. DOI: 10.1037/a0012814
Source: PubMed

ABSTRACT

Human handedness, a marker for language lateralization in the brain, continues to attract great research interest. A widely reported but not universal finding is a greater male tendency toward left-handedness. Here the authors present a meta-analysis of k = 144 studies, totaling N = 1,787,629 participants, the results of which demonstrate that the sex difference is both significant and robust. The overall best estimate for the male to female odds ratio was 1.23 (95% confidence interval = 1.19, 1.27). The widespread observation of this sex difference is consistent with it being related to innate characteristics of sexual differentiation, and its observed magnitude places an important constraint on current theories of handedness. In addition, the size of the sex difference was significantly moderated by the way in which handedness was assessed (by writing hand or by other means), the location of testing, and the year of publication of the study, implicating additional influences on its development.

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Available from: Marietta Papadatou-Pastou
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    • "Furthermore, we found evidence that a bimanual task which involves the risk of hurting oneself, if executed faultily (using a hammer to drive a nail into something), had the highest reliability of classifying handedness on its own. Bimanual tasks are assumed to confer a higher classification reliability (Papadatou Pastou et al., 2008). However, our study suggests that it may need to be a task which requires accuracy and, if executed faultily, exerts a direct negative or hurtful consequence to the individual performing it. "
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    • "Approximately 90% of humans are right-handed, with the rest made up of left-handed and ambidextrous individuals. It is well established as to singletons that the prevalence of left-handedness in males is slightly higher than that in females (Papadatou-Pastou et al., 2008). There has been a long-standing debate on the complex correlation between the development of human hand preference and brain lateralization. "
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    • "Humans exhibit sidedness preferences when performing many routine tasks (see Damerose and Vauclair 2002; Lalumière et al. 2000; Papadatou-Pastou et al. 2008). In most cases, limbs and digits on the right side are utilized more than those on the left (Carey et al. 2001; "
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