A child’s family income and the neighbourhood they grow up in may play a much bigger role in brain development than previously believed, according to a new study published in the journal Science.
Researchers at Washington University in the United States analysed brain scans from nearly 12,000 children aged nine to 10, who were part of the US National Institutes of Health-funded Adolescent Brain Cognitive Development (ABCD) Study.
They examined 649 lifestyle-related factors across 12 categories and found that socioeconomic conditions accounted for about 16% of the differences in children’s brain function.
The findings suggest that factors such as family income, housing stability and neighbourhood resources have a greater influence on brain development than individual factors like parenting style, health history or IQ.
Importantly, the researchers found that these brain differences do not reflect lower intelligence.
Instead, they appear to be linked to the long-term effects of stress and poor sleep, which are more common among children facing economic hardship.
“The brain of a child from a low socioeconomic background looks like that of a child from a high socioeconomic environment that has been sleep-deprived and stressed,” said study senior author and neurologist Prof Dr Nico Dosenbach.
Among the 40 factors most strongly connected to brain function, 37 were related to socioeconomic conditions.
Similarly, 35 of the top 40 factors linked to brain structure were socioeconomic.
Key influences included homeownership, poverty levels, access to transportation and the overall resources available in a child’s neighbourhood.
Other important factors included sleep quality, screen time and stress levels.
The study found that the areas of the brain most affected by financial hardship were those responsible for movement and sensory functions, rather than regions linked to higher-level thinking.
“If we look at children’s brain scans, we can tell how well off their family is and how much sleep and screen time they get, but we can’t tell their IQ, at least not after adjusting for socioeconomic opportunity,” said study first author and assistant professor of radiology Dr Scott Marek.
“That tells me IQ is not rooted in neurobiology.
“The environment shapes children’s brains in ways that have been misinterpreted as being reflections of IQ, when really, they’re just reflections of stress and sleep deprivation.
“Those are things we can do something about to improve kids’ brain health.”
Because poor sleep and chronic stress are key factors, community programmes and policies that help families reduce stress and improve children’s sleep could positively influence brain development and long-term outcomes. – dpa
