By Kimberly G. Noble
October 2, 2015
|Kindergarten students sing in music class at Guilford Elementary|
School in Loudoun County, Va. The school receives special federal funding
because of high rates of poverty. (Evelyn Hockstein/For The Washington Post)
What if we could draw a line from key areas of a low-income child’s brain to a policy intervention that would dramatically reduce his or her chances of staying in poverty, dropping out of school and entering the criminal justice or social welfare system? Wouldn’t we want to make that policy prescription as widely available as any vaccination against childhood disease?
Thanks to remarkable advances in neuroscience and the social sciences, we are closing in on this possibility.
In a study published this year in Nature Neuroscience, several co-authors and I found that family income is significantly correlated with children’s brain size — specifically, the surface area of the cerebral cortex, which is the outer layer of the brain that does most of the cognitive heavy lifting. Further, we found that increases in income were associated with the greatest increases in brain surface area among the poorest children.
Not surprisingly, our findings made many people uncomfortable. Some feared the study would be used to reinforce the notion that people remain in poverty because they are less capable than those with higher incomes.
As neuroscientists, we interpret the results very differently. We know that the brain is most malleable in the early years of life and that experiences during that time have lifelong effects on the mind. Work by social scientists such as Sendhil Mullainathan at Harvard University and Eldar Shafir at Princeton University has shown that poverty depletes parents’ cognitive resources, leaving less capacity for making everyday decisions about parenting. These parents are also at far greater risk for depression and anxiety — poverty’s “mental tax.” All of this has important implications for children.
When parents are distracted or depressed, family life is likely to be characterized by conflict and emotional withdrawal rather than nurturing and supportive relationships with children. Parents don’t talk and read to their kids as often and make less eye contact with them. This accumulation of stress in children’s lives has cascading effects on brain systems critical to learning, remembering and reasoning.
As a society we cannot stand by when millions of children are at risk for not reaching their full cognitive and academic potential.
So, what can we do?
First, we need definitive evidence that moves beyond correlation and helps us understand the causes of these neurological differences.
That’s why I am part of a team of social scientists and neuroscientists planning a large clinical trial in which 1,000 low-income mothers will be randomly assigned to receive either a large ($333) or small ($20) monthly income supplement for the first three years of their children’s lives. Periodic assessments of the children and their mothers will enable us to estimate the impact of these cash supplements on children’s cognitive, emotional and brain development, as well as the effect on family functioning.
Unconditional cash transfers of this sort have been tested in developing countries, with most of the evidence showing improved economic and family well-being. Research in the United States suggests that a $4,000 increase in family earnings during the first two years of a low-income child’s life is associated with remarkable differences in long-term prospects, including higher adult earnings, more hours spent in the workforce and even improved health in adulthood. To date, however, the effects of cash on children’s brain development remain untested.
Our clinical trial is designed to provide strong evidence regarding whether and how poverty reduction promotes cognitive and brain development. This study, however, will take at least five years to complete — far too long for young children living in poverty today. We should not wait until then to push for policies that can help inoculate young children’s pliable brains against the ravages of poverty.
For example, housing vouchers that allow families to move to better neighborhoods can foster upward mobility and help children escape poverty. Similarly, programs that help low-income families increase savings can pay huge dividends for low-income children. These include universal college savings account programs, currently offered in a handful of cities and states. A pilot federal program, the American Dream Accounts Act, was recently passed in the Senate as an amendment to the Elementary and Secondary Education Act. One study found that low- and moderate-income children with even less than $500 in a college savings account were significantly more likely to enroll in college and to graduate.
The political battles for major expansion of these types of programs are unlikely to be won until we can provide hard scientific proof of their effectiveness. Until then, we need to do all we can to support policies that offer our most vulnerable children the best chance of reaching their full potential.
Kimberly G. Noble is an associate professor of neuroscience and education at Teachers College, Columbia University.