Higher income may modestly positively affect child brain development

Distribution of brain wave activity (power)

High cash group got $333/month ($3996/year)

Low cash group got $20/month ($240/year)

In child development, more mid and high frequency (alpha, beta, gamma) wave activity and less low frequency (theta) correlates with improved language, memory, self-regulation, and social-emotional processing. Researchers postulated that children raised in poverty might have decreased mid and high frequency wave activity and increased low frequency activity compared to children not raised in poverty. A new study suggests this hypothesis could be true. The New York Times comments:

A study that provided poor mothers with cash stipends for the first year of their children’s lives appears to have changed the babies’ brain activity in ways associated with stronger cognitive development, a finding with potential implications for safety net policy.

The differences were modest — researchers likened them in statistical magnitude to moving to the 75th position in a line of 100 from the 81st — and it remains to be seen if changes in brain patterns will translate to higher skills, as other research offers reason to expect.  

“This is a big scientific finding,” said Martha J. Farah, a neuroscientist at the University of Pennsylvania, who conducted a review of the study for the Proceedings of the National Academies of Sciences, where it was published on Monday. “It’s proof that just giving the families more money, even a modest amount of more money, leads to better brain development.” [It’s evidence, not proof yet, because (i) this research would need to be repeated and verified, and (ii) the children would need to undergo cognitive testing to verify that the observed brain activity patterns correlate with expected cognitive function changes]

Evidence abounds that poor children on average start school with weaker cognitive skills, and neuroscientists have shown that the differences extend to brain structure and function. But it has not been clear if those differences come directly from the shortage of money or from related factors like parental education or neighborhood influences.

The study released on Monday offers evidence that poverty itself holds children back from their earliest moments.  

The question of whether cash aid helps or hurts children is central to social policy. Progressives argue that poor children need an income floor, citing research that shows even brief periods of childhood poverty can lead to lower adult earnings and worse health. Conservatives say unconditional payments erode work and marriage, increasing poverty in the long run.  

Greg J. Duncan, an economist at the University of California, Irvine, who was one of nine co-authors of the study, said he hoped the research would refocus the debate, which he said was “almost always about the risks that parents might work less or use the money frivolously” toward the question of “whether the payments are good for kids.” 

But a conservative welfare critic, Robert Rector of the Heritage Foundation, argued that the study vindicated stringent welfare laws, which he credited with reducing child poverty by incentivizing parents to find and keep jobs. “If you actually believe that child poverty has these negative effects, then you should not be trying to restore unconditional cash aid,” he said. “You certainly don’t want to go in the business of reversing welfare reform.” [Once again, mindless, rigid anti-government ideology and culture war tends to poison rationality, data interpretation and open-mindedness -- the data isn’t in yet to draw firm conclusions, and even if it was, this blowhard ideologue would still find excuses to oppose cash payments, even if (i) the evidence showed the payouts returned more to the US Treasury than the taxpayer investment, and/or (ii) regardless of what public opinion on this issue was]

One of the complexities here is trying to show that poverty causes differences in brain activity patterns, instead of just correlating with such differences. This research hints at the possibility that poverty causes the observed differences.

The research paper comments: 

Early childhood poverty has long been associated with lower school achievement, educational attainment, and adult earnings (1⇓⇓–4). Moreover, from early childhood through adolescence, higher family income tends to be associated with higher scores on assessments of language, memory, self-regulation, and social-emotional processing (5⇓⇓–8). Furthermore, poverty has been correlated with the structural development and functional activity of brain regions that support these skills. For example, higher family income is associated with a larger surface area of the cerebral cortex, particularly in regions that support children’s language and executive functioning (9, 10). This association is strongest among the most economically disadvantaged families (9), suggesting that a given increase in family income may be linked with greater differences in brain structure among economically disadvantaged children compared with more advantaged peers (11).  

However, while it might be tempting to draw policy conclusions, we caution that the present findings pertain only to the first 12 mo of a multiyear unconditional cash transfer intervention. Recent legislation and policy proposals provide income supplements to low-income families in the form of Child Tax Credit payments with higher payments in early childhood, but none would limit assistance to the first year of life (54). For our part, we do not suggest that a 12-mo intervention alone would be likely to have lasting effects, nor that cash transfer policies obviate the need for direct service interventions, such as well-child pediatric visits, home visitation, or high-quality early childhood education. Nonetheless, by targeting families during children’s earliest years, BFY [Baby’s First Years] has found important evidence of the effects of increased income during a time when children’s brains are particularly sensitive to experience. Traditionally, debates over income transfer policies directed at low-income families in the United States have centered on maternal labor supply rather than child well-being. Our findings underscore the importance of shifting the conversation to focus more attention on whether or how income transfer policies promote children’s development. (emphasis added)