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: 14.39). 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, Aug 23, 2015
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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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    ABSTRACT: Studies have repeatedly documented that 60 to 80 % of adults cradle (or carry) infants on the left side of their bodies. However, very little is known about sidedness tendencies when carrying objects in general. The present naturalistic study examines sidedness among college students as they carried books and other “academic” objects on campus. Special attention was given to sidedness biases in the use of a cradling-like carrying style. Over 2,500 observations were made of non-infant object carrying by college students in Malaysia and the United States. In both countries, females used a cradling-like carrying style much more than did males, while males predominantly carried books beside the hip. Regarding sidedness, there were significant left sided biases in the use of a cradling-like style by females in both countries and by males in Malaysia. Other sidedness differences in object carrying were also found. The left sided bias in infant carrying documented in other studies roughly resembles what this study found regarding the carrying of objects bearing no resemblance to infants, especially by females. Theories for left sided biases in infant cradling need to account for why similar biases exist particularly among females when they are carrying inanimate objects.
    Journal of Nonverbal Behavior 12/2013; 37(4). DOI:10.1007/s10919-013-0156-y · 1.77 Impact Factor
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    • "Similarly, in an earlier Greek study [9], the comparison between the sexes revealed higher proportions of left-handed boys than girls (8.26% and 6.41% respectively); nevertheless, this difference was not statistically significant. It must be mentioned however that although the sex differences in handedness are widely reported this finding is not universal [10]. Various theories have been put forward to explain the origin of handedness, and its implications for cognitive development and learning. "
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    • "Vuoksimaa and Kaprio (2010) also questioned the numerical accuracy of the contribution to the metaanalysis from (c) the Finnish study reported by Kauranen and Vanharanta (1996). Yet, we contend that Vuoksimaa and Kaprio misread Table 1 of our study (Papadatou-Pastou et al., 2008). Specifically, the odds ratio on the first of the five lines of the "
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    ABSTRACT: In response to the comment by Vuoksimaa and Kaprio (2010) on our previous article on sex differences in left-handedness (Papadatou-Pastou, Martin, Munafò, and Jones, 2008), we carried out an additional meta-analysis to explore whether the widely observed tendency for rates of left-handedness to be greater among male than female individuals is also found in Scandinavian (Nordic) studies. The overall male-to-female ratio for left- to right-handedness odds provides evidence in favor of this hypothesis. However, the results were subject to a significant moderating effect related to nation of origin. We discuss the potential impact on observed measures of additive rather than multiplicative processes that may underlie sex differences in handedness and also the date-of-study effect on handedness rates.
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