A short review on the link between poverty, children's cognition and brain development

13th March 2017

In the latest issue of the Scientific American (available here), Kimberly Noble, associate professor in neuroscience and education, reviews her work and introduces an ambitious research project that may help understand the cause-and-effect connection between poverty and children’s brain development.

For the past 15 years, Noble and her colleagues have gathered evidence to explain how socioeconomic disparities may underlie differences in children’s cognition and brain development. In the course of their research they have found for example that children living in poverty tend to have reduced cognitive skills – including language, memory skills and cognitive control (Figure 1).

Figure 1. Wealth effect

More recently, they published evidence showing that the socio-economic status of parents (as assessed using parental education, income and occupation) can also predict children’s brain structure.

By measuring the cortical surface area of children’s brains (ie the area of the surface of the cortex, the outer layer of the brain which contains all the neurons), they found that lower family income was linked to smaller cortical surface area, especially in brain regions involved in language and cognitive control abilities (Figure 2 - in magenta).

Figure 2. A Brain on Poverty

In the same research, they also found that longer parental education was linked to increased hippocampus volume in children, a brain structure essential for memory processes.   

Overall, Noble’s work adds to a growing body of research showing the negative relation between poverty and brain development and these findings may explain (at least in part) why children from poor families are less likely to obtain good grades at school, graduate from high-school or attend college.

What is less known however, is the causal mechanism underlying this relationship. As Noble describes, differences in school and neighbourhood quality, chronic stress in the family home, less nurturing parenting styles or a combination of all these factors might explain the impact of poverty on brain development and cognition.

To better understand the causal effect of poverty, Noble has teamed up with economists and developmental psychologists and together, they will soon launch a large-scale experiment or “randomised control trial”. As part of this experiment, 1000 US women from low-income backgrounds will be recruited soon after giving birth and will be followed over a three-year period. Half of the women will receive $333 per month (if they are part of the “experimental” group) and the other half will receive $20 per month (if they are part of the “control” group). Mothers and children will be monitored throughout the study, and mothers will be able to spend the money as they wish, without any constrains.

By comparing children belonging to the experimental group to those in the control group, researchers will be able to observe how increases in family income may directly benefit cognition and brain development. They will also be able to test whether the way mothers use the extra income is a relevant factor to explain these benefits.

Noble concludes that “although income may not be the only factor that determines a child’s developmental trajectory, it may be the easiest one to alter” through social policy. And given that 25% of American children and 12% of British children are affected by poverty (as reported by UNICEF in 2012), policies designed to alleviate poverty may have the capacity to reach and improve the life chances of millions of children.

NGN is looking forward to see the results of this large-scale experiment. We expect that this project, in association with other research studies, will improve our understanding of the link between poverty and child development, and will help design better interventions to support disadvantaged children.

The full article is accessible here (only to people having subscribed to the Scientific American). If you are not able to access it, you can also read this article - freely available, published in 2015 by Alla Katsnelson about Noble’s work.

If you would like to know more about the research presented here you can contact our Researcher, Florence Ruby at florence@nurturegroups.org.

 

References

  • Katsnelson, A. (2015). News Feature: The neuroscience of poverty. Proceedings of the National Academy of Sciences of the United States of America112(51), 15530–2. https://doi.org/10.1073/pnas.1522683112
  • Noble, K. G. (2017). Brain Trust. Scientific American316(3), 44–49. https://doi.org/10.1038/scientificamerican0317-44
  • UNICEF. (2012). Measuring Child Poverty: New League Tables of Child Poverty in the World’s Rich Countries