As I noted in this space yesterday, improving the health of American kids will ultimately require tackling deeply rooted social problems. But as much as the broader social environment affects each child’s health, the child’s family matters quite a bit, too. Do her parents take her to the doctor, feed her a healthy diet, and encourage her to exercise? Do his parents meet his psychological need for affection? Is she disciplined with a spanking or a time-out?

Lawrence Berger and Sarah Font explain in a Future of Children article that the answers to these questions are linked not only to parents’ income levels but also to family structure and stability. Their explanation of how these factors relate to disparities in child health is worth quoting at length:

Children who experience family complexity and fluidity tend to exhibit poorer average health and to have less access to regular health care. In part, this reflects differences in parents’ financial and behavioral resources; family complexity and fluidity are particularly common among poorer families. Moreover, higher income is associated with lower levels of psychological distress, warmer and less harsh parenting, and higher-quality caregiving environments.

At the same time, the association between family complexity and fluidity and children’s health may also reflect differences in how parents invest their financial and behavioral resources in their children. Married two-biological-parent families, for instance, not only tend to be better off, they also tend to make greater average investments in children regardless of available resources. The reason may be that biological parents have greater incentives to invest in their children, that the institution of marriage encourages better parenting, and/or that individuals who choose particular family types differ in other ways as well.

Higher-income and married biological parents also make higher-quality behavioral investments. On average, children in lower-income and complex families (loosely defined to include families other than those consisting solely of a married couple and their joint biological children) have poorer sleep routines, housing, nutritional intake, child care, home environments, schools, and neighborhoods than do children in higher-income and noncomplex families. They also receive less monitoring and harsher parenting, and are exposed to more stress, conflict, and environmental toxins both in and outside their homes. Each of these factors can adversely affect their health.

Likewise, compared with children in stably married, two-biological-parent families, children in other (heterosexual) family settings experience, on average, lower levels of parental support, supervision, and monitoring, as well as less consistent discipline. They also face greater levels of stress and parental conflict, and their parents have poorer psychological wellbeing. Each of these factors is associated with lower levels of parental support, engagement, and warmth, and limited parental attention to children’s health and emotional needs. These factors may be compounded when families experience fluidity and instability.

Long story short, kids are healthier according to a number of measures when their parents are married. But Berger and Font deem relationship education programs, which aim to increase the proportion of kids being raised by married or at least stably cohabiting parents, “unlikely to play a substantial role in improving child health and development.” They’re more hopeful about helping parents care for and supervise their kids more effectively, whatever their family structure. They examine two avenues through which public policy can do this: boosting families’ financial resources and teaching parents how to parent more effectively. Programs in the former category, particularly the earned income tax credit (a refundable tax credit for low-income workers that keeps millions of families out of poverty), have been associated with better children’s health outcomes, such as increased birth weight. Relieving financial strain might also make families more stable, which would have its own positive effects on children.

Programs in the latter category, teaching parents how to parent, have yielded mixed results. Perhaps most promising is the Nurse Family Partnership, in which registered nurses visit low-income first-time moms on a regular basis to help them achieve healthy pregnancies and become effective mothers. The program “improves maternal parenting behaviors, reduces child maltreatment and child injuries, and improves children’s social-emotional functioning,” evaluations show. Not all home visiting programs have equal success, however. Broader programs aimed at entire communities—such as public awareness campaigns and universal (one-time) nurse home visiting—are harder to evaluate and more expensive to implement, but a few have been associated with better parenting and lower rates of child maltreatment. Parent training programs outside homes seem to have only small and temporary effects, in general, according to a recent meta-analysis.

As I emphasized yesterday, there’s no easy way to ensure kids become and remain healthy. But if policy-makers on the right want to help parents do right by their children, and those on the left want to relieve poverty and close social gaps, then family-supporting programs shown to promote child health might attract wide support.