Handedness

Abstract

Asymmetry in hand use in humans takes two forms: differential hand preference and differential dexterity between the hands. People classify themselves as right- or left-handed depending on their concept of which hand they customarily use in unimanual skills for which either hand would do. When subjects’ expressed hand preference is compared to their observed differential hand use, the self-classification is found to be more skewed toward one hand than the practical reality. The preferred hand is not necessarily the one more skilled at the act in question. A variety of tests of dexterity have shown that the right hand performs better than the left but the dexterity differences between hands are not as great as differential preference would suggest, and there are in particular some self-styled left-handers who actually show superior dexterity with the right hand. Also, the nonpreferred hand is actually better in assuming certain hand postures.