Despite multiple and diverse attempts to close it, the achievement gap between the richest and poorest children remains stubbornly wide: the Education Policy Institute says that disadvantaged pupils are, on average, 18 months behind the rest of the class in academic achievement by the age of 16.

Many experts researching the link between poverty and educational underperformance have attempted to untangle the web of causes. They’ve looked at everything from a lack of books in the home to domestic violence, chronic stress and a lack of security to absent, unresponsive or poorly educated parents, poor nutrition and exposure to pollution.

More recently, though, research has been looking in more controversial areas, asking whether poverty can negatively impact on brain development. 

The research so far doesn’t claim to have any big answers - but the first findings offer a fascinating and alarming glimpse into how deep issues of income inequality go and how they can start before children enter school.

Take poor air quality, for example: we have known for some time that children in poverty are more likely to live in areas of high pollution. But a US study this year involving scanning the brains of 12-year-olds showed reduced thickness of the cerebral cortex and decreased grey matter volume in those who lived less than a quarter of a mile from a major road at age 1.

Other research involving kindergarten children found that those from low-income families performed moderately to significantly worse than their middle-class peers in cognitive tasks designed to test brain circuits responsible for language development and executive control.

One of that report’s authors, neuroscientist Professor Kimberly Noble, from Columbia University, New York, subsequently led one of the largest studies in this area, examining the brains of 1,099 people aged 3 to 18 using MRI imaging. This study found that the surface area of the cerebral cortex - the wrinkly outer layer of the brain that Noble describes as doing the cognitive “heavy lifting” - was greater for those with higher family income and parental education. This relationship was most prominent in regions of the brain that support language, reading, executive functions and spatial skills.

The study also found that among children from lower income families, small differences in income were associated with relatively large differences in surface area. Among children from higher income families, similar rises in income were associated with smaller differences in surface area.

It makes for uncomfortable reading - and this has led to some of the research failing to attract funding. Indeed, when neuroscientist Martha Farah first started looking at the relationship between brain development and income in the year 2000, she met with resistance from some parts of academia.

“I got grant reviews that said ‘You’re equating poverty with a brain disease’ or ‘You’re pathologising poor children - this is irresponsible research’,” she says. 

She got that reaction because it is easy to misunderstand the research - indeed, you may have formed opinions on it already that don’t quite fit what is actually being suggested. This is why Noble, in her TED talk about the research, was at pains to point out that the work probably does not mean what you think it means. 

“There is tremendous variability from one child to the next,” she says. “There were plenty of children from high-income homes with smaller brain surfaces and plenty of children from low-income families with larger brain surfaces. So while growing up in poverty certainly is a risk factor for a smaller brain surface, in no way can I know an individual child’s family income and know with any accuracy what that particular child’s brain would look like.”

In fact, Noble stresses that even in those children whose brains may be less well developed, neuroplasticity means that the right experiences - for example, evidence-based educational interventions in school or nursery - can change their brains.

“These differences in the child’s brain structure don’t doom a child to a life of low achievement,” she says. “The brain is not destiny.”

Clancy Blair, professor of cognitive psychology at New York University - who has looked at how the brains of children in poverty can be affected by sustained, chronic stressors - backs up this point. “The brain in poverty, in this stress response, is doing exactly what it’s meant to do,” he says. “Kids in poverty don’t have broken brains. There’s nothing wrong with these kids that a little supportive environment can’t fix.”

So far, studies have only proved correlation between adverse brain development and income, not causation - something that the researchers freely admit. That’s why, in May 2018, Noble and a group of social scientists started the Baby’s First Years study, the first randomised controlled trial to ascertain if poverty reduction causes changes in children’s cognitive and brain development.

They recruited 1,000 new mothers living below the federal poverty line, giving some of them a nominal cash payment and others several hundred dollars to spend every month as they liked for the first three years of their child’s life. “In this way we’re hoping to finally move past how poverty is correlated with child development and actually be able to test whether reducing poverty causes changes in children’s cognitive, emotional and brain development,” Noble says.

The study is yet to produce any results. But, in the meantime, other academics have highlighted that the rise of the neuroscience of poverty can at least increase awareness of the issues with those in power.

In a forthcoming paper for the journal Development and Psychopathology, Professor Seth Pollak from the University of Wisconsin-Madison, writes: “For better and for worse, issues that are framed as biomedical tend to get attention, are elevated as priorities, and receive support that is not viewed as politically partisan. Furthermore, there is evidence that neuroscience data are viewed by the general public as especially compelling.

“For these reasons, bringing brain-based measures to bear upon issues of child poverty holds potential to not only demonstrate effects of social programmes, but to also increase the likelihood that these effects are noticed and discussed by policymakers.”

But until those policymakers do make big changes that reduce poverty and its potential impacts, what can hard-pressed teachers in classrooms and early years settings do today?

Blair explains that in the case of children whose brains have become highly “reactive” because of toxic stress caused by poverty, activities that give them the chance to decide for themselves and take control can provide a foundation for future learning.

This, he concedes, isn’t always easy if a child is already suffering behavioural problems. “Granting a young child agency will work wonders… that’s essentially the key ingredient of all the programmes I’ve evaluated,” he says. “It might not promote learning initially, but it can promote learning in the long run.”

A “warm, supportive” relationship with teachers can create the conditions for stress reduction, Blair says. “It creates conditions for reflective responses to stimulation rather than reactive responses,” he adds.

But there are limits to what overburdened teachers can do on their own, explains Blair, especially if they themselves are stressed. As this research progresses, the hope is for more systemic interventions. 

“We’re asking way too much of teachers and school systems, but this is the world that we’ve made,” says Blair. 

Irena Barker is a freelance journalist

This article originally appeared in the 13 November 2020 issue under the headline “Tes focus on…the impact of poverty on pupils’ brains”