The most incisive guide to issues facing the American family today . . . An invaluable resource for anyone wishing to stay on the cutting edge of research on family trends.

-W. Bradford Wilcox
Associate Professor of Sociology, University of Virginia 

Babies with a Single Mother—and a Mental Handicap

Bryce J. Christensen and Nicole M. King

Public-health officials worry about the life prospects of infants slow to develop basic mental capacities. Such infants may begin life in many kinds of social circumstances. But in a study recently completed at Harvard and the University of Wisconsin, researchers identify family structure as one the strongest predictors of cognitive delay, which shows up much more frequently among infants born to single mothers than among infants born to married mothers.

The authors of the new study endeavor to limn the relationship between cognitive delay and the social risks of the infants manifesting such delay. To assess this relationship, the researchers scrutinize data collected for 8,950 children drawn from a nationally representative sample tracked from birth to kindergarten.

After parsing these data for the first nine months of life, the researchers identify a number of social risks associated with infants’ cognitive delay—risks that include having a mother who is impoverished, is unmarried, is a high-school dropout, is an African American, or is already the mother of three or more children. Statistical analysis demonstrates that each of these risks independently predicts cognitive delay at nine months for the infants exposed to them. 

However, in further parsing of the data, the researchers use a statistical model that assesses the impact of each risk while adjusting for the effects of all of the others. In this sophisticated model, “only single-parent household status (adjusted odds ratio [AOR] 1.34) and having three or more siblings (AOR 1.43) had significant independent associations with cognitive delay.”

In interpreting their findings, the Harvard and Wisconsin scholars indeed stress that “the independent associations between living in a single-parent household or with three or more siblings and cognitive delay provide some guidance regarding potential starting points for intervention.”

However, the two findings that the researchers underscore in their conclusions actually look quite different. Only one may actually justify intervention. To be sure, it is easy to understand why infants born with a large number of siblings might not receive much attention from their mothers (or fathers) during their first months of life—and might consequently lag in their mental development. But it is also easy to imagine how this early disadvantage might disappear as siblings become playmates, reading companions, and possibly even tutors.

But only those with an exceptionally Panglossian imagination can see a future in which children born without a father will ever enjoy a cognitive advantage in the years ahead. Realists will recognize that these children face serious cognitive handicaps in both the short and long term.

So as policymakers and social workers look for “starting points for intervention” to help reduce infants’ risk of cognitive delay, they should be especially watchful for measures that will put more infants in two-parent households. A roll-back of the legal insanity called No-Fault Divorce would be a very good starting point for intervention.


(Erika R. Cheng et al., “Cumulative Social Risk Exposure, Infant Birthweight, and Cognitive Delay in Infancy,” Academic Pediatrics 14.6 [2014]: 581-8.)