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Science Frontiers ONLINE No. 58: Jul-Aug 1988 |
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Do right-handers live longer?
"Several findings suggest that lefthandedness may be associated with reduced longevity. For instance, Porac and Coren reported that 13 per cent of 20-year-olds are lefthanded but only 5 per cent of those in their fifties and virtually nobody of 80 or above. We believe that this absence of left-handers from the oldest age groups reflects higher biological and environmental risk."
To investigate this asymmetry further, D.F. Halpern and S. Coren repaired to The Baseball Encyclopedia, where longevity and handedness are duly recorded for many players. Here again, they found that, although mortality is about the same up to age 33, thereafter about 2% more right-handers than lefthanders survive at each age.
Halpern and Coren suggest a few possible causes: (1) prenatal and perinatal birth stressors are more probable in left-handers; (2) the immune systems of lefthanders may be reduced by ge netic effects and intra-uterine hormones; and (3) left-handers may suffer more accidents in a world designed for righthanders! (Halpern, Diane F., and Coren, Stanley; "Do Right-Handers Live Longer?" Nature, 333:213, 1988.)
Reference. A variety of handedness phenomena are cataloged in BHB20-23 in Biological Anomalies: Humans I. To order this book, visit: here.