Sex distribution in sibships according to occupation of parents
Bernstein, M.E.
Genus 37(3-4): 179-188
1981
ISSN/ISBN: 0016-6987 PMID: 12264938 DOI: 10.2307/29788330Document Number: 396779
Parents in aggressive, extrovert occupations are more likely to continue procreation if the first 2 children are both female rather than male, whereas parents in humanistic or artistic occupations are more likely to continue procreation if the first 2 children are male rather than female. This relationship between occupation and reproduction decreases the percentage of unisexual sibships. Data by Renkonen et al. on sex distribution within sibships from Finland contain possibly too many sibships in which a female [F) 1st birth is followed by a succession of male [M] births. A similar excess of FMM sibships was found among the offspring of mothers engaged in high sex ratio occupations but not among the mothers engaged in low sex ratio occupations listed in Who is Who in American Women and Who is Who in the East. As shown above, there are a minimum of 2 non-genetic factors which act to decrease the percentage of unisexual sibships of 3 or more children, and the testing for sex ratio genes by utilizing sibship data should, therefore, be discontinued. It would be more advisable to test for differences in the percentage of Y chromosome bearing spermatozoa among men with differing percentages of male offspring by the technique devised by Quinlivan and Sullivan.