James Heckman, a Nobel laureate and economist at the University of Chicago, is an expert in the assessment of the economic utility of noncognitive skills.

In a 2011 paper, “The American Family in Black and White,” Heckman argues that a key factor in determining a child’s future prospects is whether he or she grows up in a one- or two-parent family, a gap that has become apparent “between the environments of children of more educated women and the environments of children of less educated women.”

Fewer than 10 percent of women with college degrees in 2011 bore children outside of marriage, Heckman writes. They

marry later and marry more educated men. They work more. They have more resources, have fewer children, and provide much richer child rearing environments that produce dramatic differences in a child’s vocabulary, intellectual performance, nurturance, and discipline. These advantages are especially pronounced for children of two-parent stable marriages. Children of such marriages appear to be at a major advantage compared to children from other unions.

In contrast, disadvantaged mothers, especially single mothers, are compromised by lack of time, money, emotional support and experience in deploying best practice parenting skills. Heckman reports that these mothers

talk less to their children and are less likely to read to them daily. Exposure to this type of parenting leads to substantial differences in the verbal skills of disadvantaged children when they start school. Disadvantaged mothers encourage their children less and tend to adopt harsher parenting styles. Disadvantaged parents tend to be less engaged with their children’s school work. The environments provided by teenage mothers are particularly adverse. Fetal alcohol ingestion alone, which is more frequent with teenage and less educated mothers, appears to have substantial deleterious consequences on adult outcomes.

In a 2014 collection, “Essays on Character and Opportunity,” Heckman, argues that the early years are crucial:

Humans are most malleable, flexible and able to learn and be imprinted by parents and culture during their first years of life.

The rewards of successful interventions with young children go beyond immediate results, according to Heckman. “Skills beget skills,” he writes, pointing out that

investments today increase the stock of future skills, which in turn increases the return to future investments — a phenomenon known as dynamic complementarity.

Paul Tough, a writer heavily influenced by Heckman’s work, noted last year in an essay in the Atlantic, “How Kids Learn Resilience,” that research reveals that “students will be more likely to display these positive academic habits when they are in an environment where they feel a sense of belonging, independence, and growth” and where they “experience relatedness, autonomy, and competence.”

This kind of environment is difficult to replicate in neighborhoods of concentrated poverty. Instead, Tough writes, many of the kids brought up in these desolate areas have developed “a hyperactive fight-or-flight mechanism,” which conveys the warning

at car-alarm volume: I don’t belong here. This is enemy territory. Everyone in this school is out to get me. Add to this the fact that many children raised in adversity, by the time they get to middle or high school, are significantly behind their peers academically and disproportionately likely to have a history of confrontations with school administrators.

The result is a vicious circle: family disruption perpetuates disadvantage by creating barriers to the development of cognitive and noncognitive skills, which in turn sharply reduces access to college. The lack of higher education decreases life chances, including the likelihood of achieving adequate material resources and a stable family structure for the next generation.

There is substantial data describing this vicious circle.

A 2013 Bureau of Labor Statistics analysis of marital status for men and women at the age of 46 found that the divorce rate for those with only a high school diploma, 49 percent, is twice that of college graduates, 23.7 percent. The less well educated marry younger, 24.8 years, than college grads, 27.2 years.

An even sharper split has developed in recent years in terms of marriage rates and the proportion of nonmarital births — a topic I approached last week in the context of problems specific to men. A 2016 study published by the National Institutes of Health, “Diverging Patterns in Marriage, Cohabitation, and Childbearing,” shows that the problem crosses gender boundaries. The N.I.H. study found that in 1950, there was very little difference between the family arrangements of high school and college graduates, aged 30 to 44: 70 percent of the women with college degrees were married, as were 80 percent of those with high school degrees. By 2010, marriage rates had fallen down to 56 percent for those who had no more than high school degrees, but dropped by only one percentage point among college graduates.