Family patterns in handedness: evidence for indirect inheritance mediated by birth stress.
The most common alternative to a genetic explanation of left-handedness is that sinistrality arises because of birth stress factors. In a sample of 1398 subjects, the association between birth stress and left-handedness was confirmed. More importantly, it was found that left-handed mothers are more likely to have birth-stressed offspring and that the presence of any left-handed sibling increases the likelihood of a history of birth stress in the proband. This was interpreted as suggesting that a plausible alternative to the genetic explanation for the usual pattern of association observed in family studies of handedness (where a left-handed mother increases the probability of left-handed offspring) is that the mother-offspring association may actually be mediated by birth stress rather than representing heritable aspects of handedness.
Department of Psychology, University of British Columbia, Vancouver, Canada.
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D000293:Adolescent; D000328:Adult; D005260:Female; D005316:Fetal Distress / Q000150:complications* / Q000235:genetics; D007839:Functional Laterality / Q000235:genetics*; D005838:Genotype; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D018566:Pregnancy, High-Risk; D011336:Probability; D012307:Risk Factors