Can Cash Allowances Help Kids' Brains Grow?
Ever since the election of a Republican majority in Congress in 1994, the trend in assistance to the poor has been to reduce it. Work requirements for recipients, time limits on assistance and stricter eligibility conditions to receive food stamps were all part of the 1996 welfare reform overhaul signed by President Bill Clinton. The result was fewer kids receiving aid, and those who did received less money. In 2015, while 15 million American children, or about 21 percent, grow up in homes with incomes below the official poverty line—which many children’s policy experts maintain is set far too low—just 2.3 million of them received welfare benefits, down from a peak of 9.5 million in 1993. (The poverty rate was even higher in California.)
But what if mothers in poverty received a cash handout every month, beginning shortly after they gave birth—no questions asked? And what if, by enabling those moms to buy toys or books, move to a different neighborhood, afford better childcare, attend continuing education classes, or just reduce the amount of stress they experience from not having to worry about money all the time, those extra funds resulted in their children’s brains growing more than they would have without the money?
That’s the idea behind a groundbreaking study conceived by Greg J. Duncan, an economist at University of California, Irvine who studies the relationship between family income and children’s achievement and attainment as adults. Already five years in to the work, Duncan and the team of three social scientists and one neuroscientist he has assembled hope to begin recruiting subjects next year.
“Politically, the question is very important,” said Katherine Magnuson, an associate director of the Institution for Research on Poverty at the University of Wisconsin, Madison and one of the designers of the study. “People in Washington talk about the pluses and minuses of programs that put money in people’s pockets or take it out, and we need to understand the consequences of their decisions in terms of children.”
Evidence that poverty manifests in children’s development has been building for years. “Childhood socioeconomic status is strongly associated with IQ, graduation rates and test scores,” said Kimberly G. Noble, MD Ph.D., the team’s neuroscientist and a pediatrician and associate professor of neuroscience and education at Columbia University’s Teachers College. The gap emerges early and widens through the elementary school years. Children who score poorly relative to other students on intelligence assessment but come from families of high socioeconomic status—which combines income, parent education level, parent occupation and occupational prestige—see their scores go up, relative to other kids, over time; kids who score high early on but are in low socioeconomic-status families see their scores fall.
Early in her career, Noble wanted to know which particular cognitive skills were associated with socioeconomic status. A 2007 paper she and colleagues published in Developmental Science showed that the greatest differences were in language, memory and executive function (the ability to plan and focus). Just the skills, in other words, most needed in a 21st century economy.
That led Noble to more questions: “How do differences in cognitive skill relate to differences in brain structure?” In 2012, she and colleagues found that higher family income is associated with a larger hippocampus, the part of the brain believed to govern memory and emotion. Income was also found to correlate with larger surface area of the brain, especially in those parts associated with executive function and language.
In 2015, Noble published data that extended this finding to the cerebral cortex. Four labs, independently of one another, have since replicated this research. While it wouldn’t be possible to predict a kid’s brain size from his parents’ income—plenty of kids from well-off homes had smaller surface areas to their brains than some of the kids in poorer homes—Noble’s paper showed the effect was strongest among the most disadvantaged children. “The proportional differences in income were associated with greater differences in brain structure among the worst-off kids,” she said.
Media trumpeted the research with headlines like, “How Poverty Changes the Brain.” But Noble knew that her results were only associational. “We can say differences in family income are associated with differences in brain structure but we can’t say what’s causing what,” she said. “Is it other things, meaning that changing income might not make a difference?”
Then, several years ago, fate intervened. Noble met with a graduate student whom Columbia had randomly matched her with to mentor, and they got to chit-chatting. The student asked about her research, and after Noble answered, she recalls, the student mentioned that her father does similar work, but as an economist. “Well, there’s like one economist in the world, maybe two, who fits that description,” Noble said. “So I looked at her ID badge and said, ‘Wait—is your dad Greg Duncan?’”
It was, and he happened to be in New York at the time. So the two professors had lunch.
“I’d always wanted to meet her,” Duncan said of Noble. He knew that a $4,000 increase in annual income prenatally to age 2 can mean a 19 percent increase in the child’s earnings as an adult. He told her of an idea of his: What if they could do an experiment that alleviates poverty and test causally the effects on child development? “She knew what the problem was with non-experiential data,” Duncan said. “A lot of neuroscientists in this area take the work and say ‘poverty destroys brains,’ but she understood the value of random assignment.” Noble told Duncan that if he ever developed this idea into an experiment, count her in.
Duncan soon spoke to some social scientists he had worked with before and assembled a team with the right combination of skills necessary to pull off a study to measure the effects of income on the developing brain during the first three years of life. They would need to find subjects, evaluate parent stress and parent involvement, and—Noble’s specialty—measure brain activity.
Their study will recruit mothers who are in hospitals to give birth, with incomes no greater than the federal poverty threshold, and randomly assign them to one of two groups: Members of the treatment group will receive $333 per month as an automatic deposit on a debit card. Mothers in the control group will receive $20 per month. The researchers plan to recruit 250 new moms at each of four sites, chosen to represent a diversity of state benefits offered and of racial or ethnic composition, among other things. After they secure agreements to participate, researchers will interview the moms for 20 minutes. “You’d be surprised at how hard it is to give away money,” said Magnuson, who is a former student of Duncan’s. Special legislation had to be passed in Nebraska and Minnesota, two of the study sites, so the income would not threaten participants’ eligibility for public benefits and thereby negate the “treatment.”
At 12 months, researchers will conduct a longer interview by telephone. When the children reach age 2, the researchers will conduct home visits and collect hair and saliva samples to test them for cortisol levels, an indicator of stress that has been shown to damage the developing brain. Researchers will also videotape the mothers’ interactions with their children during a standardized play task; the videos will be coded for different aspects of parent sensitivity such as perceiving gestures from their children and picking up and responding to them. “We expect to see more sensitive reciprocal interaction in the parents in the treatment group,” Duncan said. At age 3, the families will be brought into the lab to measure cognition and brain development in detail, using EEGs.
Noble would have liked to begin the study prenatally, but that would have risked missing women who weren’t receiving prenatal care. “Almost everyone in the U.S. gives birth in a hospital, but the degree to which mothers receive prenatal care varies quite a bit,” she said. Walking up to women with big bellies on the street wouldn’t have been practical. “If there was a way to get everyone prenatally, for sure we would have loved to try that,” Noble said.
Another limitation of the study will be the use of EEG instead of MRI data—or, better yet, examining the brains directly, which you can do with monkeys but not humans. Older kids can be relied upon to sit still in the noisy, dark MRI tubes, but 3 year olds not so much. An EEG scan involves a series of electrodes fitted into a cap that is placed on the child’s head. “Most kids don’t mind it,” Noble said. “They can sit on their caretaker’s lap. It gives a pretty good window into the electric brain function.”
Children who grow up in more well-off families have vastly different experiences than those in poverty today. Living in a poor neighborhood has been shown to have physiological effects: A mother’s address at pregnancy predicted cortisol response and length of telomeres, DNA sequences that protect chromosomes, in their children at 12 months. The poor tend to live in more polluted areas, increasing exposure to toxins, and in more crowded and less stable housing environments, which can cause stress. They may live in violent neighborhoods; exposure to violence has been shown to affect the length of children’s telomeres, effectively aging them prematurely, according to research published in 2012 in Molecular Psychiatry. Poor moms have higher rates of psychological distress and depression, which can affect how they interact with their children. They tend to be in lower-quality childcare if they are in childcare, and to have less stable family relationships.
“None of this is to say poor children don’t often live in incredibly loving and warm families who do their best to support their children,” Magnuson emphasized. “But it’s hard to be the parent of a young child in our country—there are very few supports for it—and incredibly hard to do it with very limited financial resources.”
The debit cards will show how participants are spending the money, but not what they spend it on; researchers will need to rely on surveys for that information. They are trusting that families are “able to optimize and understand their own needs,” Magnuson said. Some moms might put their kids in better quality childcare; others might spend the money on ESL classes. Some may decide to move into an apartment in a safer neighborhood; others may calculate they can afford to delay returning to work and thereby spend more time with their infant. The money is expected to just generally reduce mothers’ stress. “If they’re less depressed maybe they’ll have more bandwidth to talk more to their children, or take them to the library,” Magnuson suggested. “Anything that’s going to reduce the child’s experience of stress could very likely improve their brain development.” The surveys, physiological samples and videotaped interactions should provide such data.
“Greg and I have been studying child poverty for a lot of years, particularly Greg,” Magnuson said. “We come from the perspective of wanting to know if something is causal or not, because you want to know how much money really does matter. We’re not here to find something that doesn’t exist. Then I’ll think of other ways to help children.”