The diminished number of older left-handers: differential mortality or social-historical trend?
Recent research suggests that left-handers have shorter life spans. This interpretation could be erroneous if there is a social-historical trend in handedness with older individuals more frequently switched to right-handedness. This would result in fewer older left-handers due to social factors. Two samples (N = 1960 and N = 8526), separated by a 12 year interval were tested. Social-historical hypotheses predict that the later sample should have higher proportions of left-handedness. Although both samples showed decreased sinistrality with age, there was no increase in the proportion of left-handers over the 12 year period, suggesting that the rarity of older left-handers is due to reduced longevity.
Coren
S
S
Psychology Department, University of British Columbia, Vancouver, Canada.
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008017:Life Expectancy; D008136:Longevity / Q000502:physiology; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D012107:Research Design