Family income may influence kids' brain development
Socio-economic influences Family income has an impact on children's brain development particularly among those from parents earning lower incomes, a US study suggests.
The finding has the potential to impact on government policies as it suggests programs aimed at reducing family poverty may have meaningful effects on children's brain functioning and cognitive development.
While socio-economic factors have previously been linked to cognitive function, this latest study, published today in Nature Neuroscience , attempts to see how socio-economic factors influence brain structure.
For the study the team isolated two distinct socio-economic factors -- parental education and family income -- and their affect on brain surface area and cortical thickness.
These brain structures were selected because "intelligence has been associated with the trajectories of both cortical thickness and surface area", the researchers say in the paper.
"By age 10, more intelligent children have thinner cortices; this relationship becomes more pronounced through adolescence. In contrast, surface area is greater in more intelligent children at age 10," they write.
More than 1000 children aged between three and 20 years were involved in the study, which included a questionnaire for parents on education and income, cognitive testing of the participants, DNA testing for ancestry and brain imaging.
While the study finds increases in parental education and family income are both associated with increases in brain surface area, it appears family income has a stronger relationship.
Co-author Associate Professor Kimblerly Noble, of Colombia University in New York, says the relationship between income and brain surface area is greatest at the lower end of the family income scale.
For every dollar increase in income, the increase in brain surface area was proportionally greater in children from the lower end of the family income spectrum than those from higher income families.
"Dollar for dollar, we see a greater increase in surface area among the most disadvantaged children," says Noble.
The impact was particularly noted in regions of the brain associated with language and executive functions such as memory and problem solving.
The researchers acknowledge further work is needed to understand the underlying mechanisms behind this impact.
They point out it these results may reflect that those earning higher incomes have the "ability to purchase more nutritious foods, provide more cognitively stimulating home learning environments, and afford higher-quality child care settings or safer neighbourhoods, with more opportunities for physical activity and less exposure to environmental pollutants and toxic stress".
The team stresses however their findings "should in no way imply that a child's socioeconomic circumstances lead to an immutable trajectory of cognitive or brain development".
"Many other factors account for variance in brain morphometry. Certainly both school-based and home-based interventions have resulted in important cognitive and behavioural gains for children facing socioeconomic adversity."
Noble says her research team is currently collaborating with a team of social scientists and neuroscientists to test how these findings may be used to benefit children in lower-income families.
"We are proposing to recruit a national sample of low-income mothers, randomise half to receive a large monthly payment and half to receive a modest monthly payment, and assess the causal impact of this income supplementation on children's cognitive and brain development.
"If evidence supports our hypotheses, then it would suggest that governments would be well served to increase the generosity of social services for the most disadvantaged families," says Noble.