New research that shows poor children have smaller brains than affluent children has deepened the national debate about ways to narrow the achievement gap. Neuroscientists who studied the brain scans of nearly 1,100 children and young adults nationwide from ages 3 to 20 found that the surface area of the cerebral cortex was linked to family income. They discovered that the brains of children in families that earned less than $25,000 a year had surface areas 6 percent smaller than those whose families earned $150,000 or more. The poor children also scored lower on average on a battery of cognitive tests. The region of the brain in question handles language, memory, spatial skills and reasoning, all important to success in school and beyond.
The study, published last month in Nature Neuroscience, is the largest of its kind to date. It was led by Kimberly Noble, who teaches at both Columbia University’s Teachers College and the university’s medical school. Elizabeth Sowell, of Children’s Hospital Los Angeles, was the senior author. “We’ve known for so long that poverty and lack of access to resources to enrich the developmental environment are related to poor school performance, poor test scores and fewer educational opportunities,” Sowell said. “But now we can really tie it to a physical thing in the brain. We realized that this is a big deal.”