Professionally written biographies of 353 women selected for inclusion in two volumes of a dictionary of biography were analyzed separately for data on family structure, occupation, and personality characteristics. Findings from Volume 4 (1921-1940) were similar to those from Volume 5 (1941-1960). Results showed that 55.2% of women biographees had no children. They were either unmarried or, if married, childless. Of those who did have children, biographees had a significantly high ratio of sons to daughters compared with the norm (0.514) (Vol. 4: males = 106, females = 76; Vol. 5: males = 115, females = 80; totals: males = 221, females = 156; chi2 = 7.87; p = 0.005). These data, interpreted according to the maternal dominance hypothesis (Grant 1998) and set in the context of increased workforce participation by women and declining fertility, suggest another possible explanation for the contemporary decline in the secondary sex ratio.