Numerous studies have linked poverty with impaired cognitive development, but to date little is known about how socioeconomic status might relate to the physical development of the brain. In a recent study, published in Nature Neuroscience, Columbia University researchers Kimberly Noble, Suzanne Houston and their colleagues completed the largest investigation of socioeconomic status and children’s brain structure to date.
The researchers found both parental education and family income to be associated with a child’s brain structure—particularly in regions critical to language, executive functions and memory. To explore the link between socioeconomic factors and brain structure, the researchers examined the surface area of the cortex—collected from over 1000 youth ranging in age from 3 to 20, as a part of the multi-site Pediatric Imaging, Neurocognition and Genetics study—in relation to family income and parental education, while controlling for age, sex, and genetic ancestry.
Children whose parents spent more years in high school or college showed increased brain surface area compared to children whose parents experienced lower levels of education. The relationship between parental education and surface area followed a linear path, “implying that any increase in parental education, whether an extra year of high school or college, was associated with a similar increase in surface area over the course of childhood and adolescence.”
Similarly, children with higher family income also tended to have increased brain surface area. However, the relationship between income and surface area was not linear, but rather logarithmic, meaning the increase in brain surface area per dollar earned was comparatively greater for children from lower earning families than for those from more financially well off households.
Understanding the link between socioeconomic status and experience-dependent brain development is an important step for both researchers and policy makers looking for ways to close the achievement gap. However, it should be noted that the present study does not identify a causal link between socioeconomic status and brain structure—it does not identify what socioeconomic related experiences impact brain development. The question remains how factors like stress, nutrition, exposure to environmental toxins, or cognitive stimulation impact a child’s brain in her prenatal environment and/or her post natal environment.
Finally, the authors make a point of stating, “Our results should in no way imply that a child’s socioeconomic circumstances lead to an immutable trajectory of cognitive or brain development.” They point out there are a number of other factors that explain differences in brain development. Nevertheless, they conclude, “Many leading social scientists and neuroscientists believe that policies reducing family poverty could have meaningful effects on children’s brain functioning and cognitive development.”
- Noble, K. G., Houston, S. M., Brito, N. H., Bartsch, H., Kan, E., Kuperman J. M., …Sowell, E. R. (2014). Family income, parental education and brain structure in children and adolescents. Nature Neuroscience. Advanced online publication. doi: 10.1038/nn.3983