Left-right discrimination in medicineBMJ 2008; 337 doi: https://doi.org/10.1136/bmj.a2906 (Published 16 December 2008) Cite this as: BMJ 2008;337:a2906
- Chris McManus, professor of psychology and medical education
- 1University College London, London WC1E 6BT
Right and left are so very confusing. Perceptually, distinguishing right and left is surprisingly difficult, as Gormley and colleagues’ linked article shows (doi:10.1136/bmj.a2826).1 Scientifically the origins of a brain polymorphism that makes 90% of people use their right hand for skilled activities but the other 10% use their left hand are unclear.2 And socially, ethically, and educationally, there is confusion over the needs and rights of those people whom I sometimes describe as the last great neglected minority—left handers.
Right handedness is so obvious a fact of life that few people realise how unusual it is. All other species, except perhaps chimpanzees,3 are made up half and half of right handers and left handers. Nor is it coincidence that humans alone have language, and that language is mostly located in the left hemisphere, which controls the right hand. The left hemisphere processes information more quickly than the right hemisphere. This speed is required both for online processing of grammar and the …