Sex distribution in sibships according to occupation of parents

The relationship between sex distribution in sibships and the occupation of parents is examined to determine if nongenetic factors influence sex ratios in families of three or more children. The study is based on data for 2,759 families listed in the U.S. reference book "Who Is Who in the East", as well as additional data from "Who Is Who in American Women". It is found that "parents in aggressive, extrovert occupations are more likely to continue procreation if the first two children are both female rather than male, whereas parents in humanistic or artistic occupations are more likely to continue procreation if the first two children are male rather than female. This relationship between occupation and reproduction decreases the percentage of unisexual sibships." (summary in FRE, ITA)