The Science of Early Adversity

article image
Early adversity, says Charles Nelson, a neuroscientist and professor of pediatrics at Harvard Medical School, can interfere with “planning ability, cognitive flexibility, [and] memory, and all of those will correlate with diminished IQ.”

For a long time, social science has known of correlations between childhood turmoil and adult maladies that carry massive social and financial costs–mental illness, addiction, tendencies toward violence. And for decades, society has attempted to address those problems with a variety of social interventions including Head Start, which aims to prepare low-income kids between ages 3 and 5 for school; investments in school-age children; and programs for rehabilitation of juvenile delinquents.

But a scientific revolution that has taken place in the past decade suggests that many of the dysfunctions associated with childhood have roots earlier than is commonly understood–especially during the first two years of life.

Like all living creatures, human babies are hardwired with a stress reaction that kicks in whenever they perceive a threat, which can be as simple as hunger or the feeling of a wet diaper. Deep inside the adrenal glands, which sit atop the kidneys, cells pump out adrenaline–a hormone that makes the lungs breathe and the heart beat faster, increasing the supply of oxygen to the muscles.

With these hormones sloshing around, blood pressure rises, muscles tighten, energy surges, and a baby wails. When comfort comes quickly, the body produces fewer stress hormones and the brain goes back to business as usual. And if this happens repeatedly, as it should, the nerve impulses crackling in the brain will build pathways that the baby can use later in life to solve problems and overcome difficulty.

But the baby who is ignored or neglected just keeps screaming and flailing. Eventually, he exhausts himself and may appear to withdraw. Yet the quiet child is not a content child. Constant activation of the stress system causes wear and tear on the brain, so that coping and thinking mechanisms don’t develop in the same way.

Early adversity, says Charles Nelson, a neuroscientist and professor of pediatrics at Harvard Medical School, can interfere with “planning ability, cognitive flexibility, [and] memory, and all of those will correlate with diminished IQ.” Some of the children who go through these experiences end up OK–and later interventions may still be helpful for those who struggle. But, overall, says Nelson, “they’re more likely to have mental health problems.”

And these struggles, naturally, lead to other problems that perpetuate the cycle of poverty.

In the early 1990s, Diana Menley Rauner left a lucrative career in private equity to study developmental psychology at the University of Chicago. For her dissertation, she visited day care centers in the city, hoping to learn about how infants and toddlers pick up language skills. But she learned a lot more about the sorry state of child care. Rauner described facilities where infants were strapped in car seats, “watching The Lion King all day,” while the older kids were “circling the room almost like sharks” and throwing things at the infants, because they had nothing else to do. But the infants frequently didn’t cry. “A lot would just stare, which is almost worse,” Rauner says.

Today, Rauner runs the nonprofit Ounce of Prevention Fund, a $46 million-per-year initiative that applies the latest scientific findings about early childhood to help some of Chicago’s most disadvantaged families. The fund trains workers at day care centers to nurture babies in ways that will stimulate positive brain activity. It also operates its own child care center and school, called Educare, that became the model for a national network of such facilities designed to improve day care for infants and young children, including those too young for Head Start.

Perhaps the program’s most intriguing initiative is its work with agencies that provide at-home visits to young women, particularly teenagers, who are either pregnant or are new mothers. The model for these visits is a nursing program that David Olds, a University of Colorado pediatrician, tested in Elmira, New York, during the 1970s and 1980s, and that grew into the national Nurse-Family Partnership. In 2011 the program, which the federal government helps finance, will serve more than 20,000 families; they receive home nurse visits from when they become pregnant until their children are 2 years old. Olds’ program is one of the more unambiguous success stories in the modern history of social policy. Two long-term studies published in the Journal of the American Medical Association found that adolescents whose mothers had been in the program were less likely to run away, get arrested, or consume alcohol or tobacco. Reports of child abuse were lower by about 50 percent.

When the RAND Corporation evaluated the initiative, it determined that the program would save between $1.26 and $5.70 for every $1 spent, with the higher savings from the higher-risk families, thanks to reduced spending on hospitals, incarceration, and cash assistance. And according to Timothy Bartik, an economist and author of Investing in Kids, every dollar that goes into the Nurse-Family Partnership will raise incomes for the New York population by $1.85 per dollar of costs, once you factor in the economic benefits of a more productive workforce–and a tax base that won’t be so strained picking up the tab for remediation and crime.

The science of early adversity, then, offers a blueprint for tackling the effects of poverty and neglect, one that is more precise and observable than any tools policy makers have ever had at their disposal. “The concept of disrupting brain circuitry is much more compelling than the concept that poverty is bad for your health,” says Jack Shonkoff, a Harvard pediatrician and chair of the National Scientific Council on the Developing Child. “It gives us a basis for developing new ideas, for going into policy areas, given what we know, and saying here are some new strategies worth trying.”

Jonathan Cohn is a senior editor at The New Republic. Excerpted from The New Republic(December 1, 2011), a Washington, D.C.-based magazine founded in 1914 to critically evaluate politics, foreign policy, and culture.

In-depth coverage of eye-opening issues that affect your life.