Family income might be associated with brain structure, reports a study published online this week in Nature Neuroscience. The study finds this association to be strongest among children from lower-income families.
Although socioeconomic status has been associated with cognitive development, it is unclear how it may affect underlying brain structure. Kimberly Noble, Elizabeth Sowell and colleagues investigated the relationships between brain structure, family income, and parental education in a sample of more than 1,000 typically developing children and adolescents between three and 20 years old.
The authors controlled for potential differences in brain structure related to ancestral origin by collecting DNA samples from each participant. They found that increases in both parental education and family income were associated with increases in the surface area of brain regions implicated in language and executive functions. However, family income appeared to have a stronger, positive relationship with brain surface area than parental education. Brain surface area also seemed to account partially for the associations between family income and the children’s performance on tests of working memory and executive function.
While these findings suggest a relationship between socioeconomic status, brain surface area and performance on cognitive tasks, the mechanism by which these factors may influence each other is undefined. These results in no way imply that a child’s socioeconomic circumstances lead to an immutable trajectory of cognitive or brain development.