Marital status and reproduction: Associations with childhood intelligence and adult social class in the Aberdeen children of the 1950s study

Childhood intelligence (age 11) and occupational social status at midlife (age 46 to 51) was associated with marital status and reproduction in a sample from the Aberdeen Children of the 1950s cohort study (N = 9614).Male and female divorcees had lower childhood intelligence test scores than their married counterparts, but no meaningful difference was found between ever- and never-married individuals. Lower occupational social status increased the odds of being never-married, divorced, separated or widowed compared to being married by 53% to 26% in men (N = 2716) but not in women (N = 2920). Higher intelligence scores were associated with being married rather than divorced at midlife with odds ratios (OR) of 0.86 (Confidence Interval of 95% of 0.76 to 0.99) in men, and 0.87 (0.77 to 0.98) in women.In men, lower intelligence predicted having offspring (0.69; 0.59 to 0.81), while in women, higher occupational status was associated with lower odds of having children (0.66; 0.55 to 0.76). An interaction term showed that high intelligence women remained childless in the top occupational classes but, in the lower social groups, mothers were more intelligent than their childless peers. Intelligence or occupational status were not associated with the number of offspring in both sexes.

► Ever- and never-married men and women did not differ in childhood intelligence, but lower childhood IQ was associated with higher rates of divorce more unstable marital relations at midlife.
► Men, who did not father biological children, were on average more intelligent than those with biological children.
► Childless women were more intelligent than mothers in higher, but not in low social occupational classes.