Many years of research have shown that for students from lower-income families, standardized test scores and other measures of academic success tend to lag behind those of wealthier students.

A new study led by researchers at MIT and Harvard University offers another dimension to this so-called “achievement gap”: After imaging the brains of high- and low-income students, they found that the higher-income students had thicker brain cortex in areas associated with visual perception and knowledge accumulation. Furthermore, these differences also correlated with one measure of academic achievement — performance on standardized tests.

“Just as you would expect, there’s a real cost to not living in a supportive environment. We can see it not only in test scores, in educational attainment, but within the brains of these children,” says MIT’s John Gabrieli, the Grover M. Hermann Professor in Health Sciences and Technology, professor of brain and cognitive sciences, and one of the study’s authors. “To me, it’s a call to action. You want to boost the opportunities for those for whom it doesn’t come easily in their environment.”

This study did not explore possible reasons for these differences in brain anatomy. However, previous studies have shown that lower-income students are more likely to suffer from stress in early childhood, have more limited access to educational resources, and receive less exposure to spoken language early in life. These factors have all been linked to lower academic achievement.

In recent years, the achievement gap in the United States between high- and low-income students has widened, even as gaps along lines of race and ethnicity have narrowed, says Martin West, an associate professor of education at the Harvard Graduate School of Education and an author of the new study.

“The gap in student achievement, as measured by test scores between low-income and high-income students, is a pervasive and longstanding phenomenon in American education, and indeed in education systems around the world,” he says. “There’s a lot of interest among educators and policymakers in trying to understand the sources of those achievement gaps, but even more interest in possible strategies to address them.”

Allyson Mackey, a postdoc at MIT’s McGovern Institute for Brain Research, is the lead author of the paper, which appears the journal Psychological Science. Other authors are postdoc Amy Finn; graduate student Julia Leonard; Drew Jacoby-Senghor, a postdoc at Columbia Business School; and Christopher Gabrieli, chair of the nonprofit Transforming Education.

Explaining the gap

The study included 58 students — 23 from lower-income families and 35 from higher-income families, all aged 12 or 13. Low-income students were defined as those who qualify for a free or reduced-price school lunch.

The researchers compared students’ scores on the Massachusetts Comprehensive Assessment System (MCAS) with brain scans of a region known as the cortex, which is key to functions such as thought, language, sensory perception, and motor command.

Using magnetic resonance imaging (MRI), they discovered differences in the thickness of parts of the cortex in the temporal and occipital lobes, whose primary roles are in vision and storing knowledge. Those differences correlated to differences in both test scores and family income. In fact, differences in cortical thickness in these brain regions could explain as much as 44 percent of the income achievement gap found in this study.

Previous studies have also shown brain anatomy differences associated with income, but did not link those differences to academic achievement.

“A number of labs have reported differences in children’s brain structures as a function of family income, but this is the first to relate that to variation in academic achievement,” says Kimberly Noble, an assistant professor of pediatrics at Columbia University who was not part of the research team.

In most other measures of brain anatomy, the researchers found no significant differences. The amount of white matter — the bundles of axons that connect different parts of the brain — did not differ, nor did the overall surface area of the brain cortex.

The researchers point out that the structural differences they did find are not necessarily permanent. “There’s so much strong evidence that brains are highly plastic,” says Gabrieli, who is also a member of the McGovern Institute. “Our findings don’t mean that further educational support, home support, all those things, couldn’t make big differences.”

In a follow-up study, the researchers hope to learn more about what types of educational programs might help to close the achievement gap, and if possible, investigate whether these interventions also influence brain anatomy.

“Over the past decade we’ve been able to identify a growing number of educational interventions that have managed to have notable impacts on students’ academic achievement as measured by standardized tests,” West says. “What we don’t know anything about is the extent to which those interventions — whether it be attending a very high-performing charter school, or being assigned to a particularly effective teacher, or being exposed to a high-quality curricular program — improves test scores by altering some of the differences in brain structure that we’ve documented, or whether they had those effects by other means.”

The research was funded by the Bill and Melinda Gates Foundation and the National Institutes of Health.

As we are told anytime homosexuality is being discussed, variability in essentially all behavioral traits has some genetic basis.

There is no reason to believe that the behavioral traits that lead to academic excellence (intelligence+effort) are any different. On average, parents who are economically successful have achieved greater academic success than parents who have been economic failures. Thus the economic success is due to behavioral traits that are, in part, due to genetic endowment. That endowment is passed on to their children.

It takes a PC induced insanity to claim that the children of a community made out of high school dropout truck drivers and maids are likely to have the same innate intellectual ability as the children of a community made up of Harvard educated lawyers and MIT educated engineers.Trying to claim, without evidence, that it is "poverty" which causes differences in brain structure and that causes reduced intellectual achievement is the Progressive's version of the idiot Right's romance with Creationism. Poverty is the result of a host of behavioral factors, not the cause.

There's a lot of assertion here that the causes of these differences are environmental. Sadly, it doesn't look like there's much in the way of evidence.

It's uncomfortable for people to entertain this possibility, but it could be genetics. Assortative mating for income and IQ is a thing, and it would nicely explain a widening achievement gap as the third generation of children from two-income households begin to move through school.

Honestly, a biological cause would be easier to fix -- it'd be way easier find a drug that gives everyone 5 more IQ points and slip it into the drinking water than it would be than to interfere with the home lives of millions of children.

So children of those that know how to make decisions to be successful in life also demonstrate the skills and abilities to be successful. And vice-versa. And the continuance over time of certain cultures to follow each of those paths separates the groups further as those groups either continue to learn and adapt to be successful, or choose not to. That's not startling whatsoever, and not a result of "educational programs." It's from their parenting, environment and support systems.

The ministry of truth will not tolerate any breach of their misinformation campaign-- this article must be eradicated. I'm a teacher. We're routinely told in professional development that disappointing student results are our fault.This article directly contradicts ample brainwashing on the part of the education training industry and will not be tolerated. Who are you scientists to stick your nose in where only politics belongs anyway?

I think they need to do a much broader and more robustly defined study group to really assert any of the conclusions they have come to listed here. It does point to a troubling issue however, and one we should definitely get to the bottom of.

The Bell Curve explained all this in 1992 but it's a banned book so everyone is afraid to read it. There's nothing at all surprising here if you read the Bell Curve.

I would like to see this repeated with a far larger sample size

OK, not a statistician or ... BUT is a study of 58 individuals very meaningful for drawing any conclusions? Seems like a very small study. Where did the students live? Grow up? What was done to eliminate other factors? I read so many conclusions from this or that study in the news that I feel inclined to dismiss all of them as premature, or even utter nonsense. Is this better?

As a quasi statistics professional, I distrust practically all of the observations/conclusions reported. The variables are far too numerous as well as undefined. Another waste my time effort that should be pared down and restudied in much smaller windows with giant sample sizes.

Did this study consider the critical factors of decent and sustained access to quality prenatal care and the importance of early childhood nutrition?

Small sample size is absurd when you are looking at a dependent variable you know little about. Further, even conceptually there are problems. Doesn't make a lot of sense if they are implicating stress. While the stressors are different, children from higher (middle class) SES homes are not necessarily under less stress (although they may be different ones) -they should be using ANCOVA or Regression instead of simple ANOVA designs.

thanks for all the work for children

They clearly need to do a separated twin study here.

This is not even remotely surprising. Wealthy parents have access to way more stimulating environments for their students; they are able to pay forbiddingly high fees for special programs and purchase any books/materials that their students are interested in. And for what? So they can boast that their students are in X, Y, Z special program(s)?? This is what happens when you infuse corporate capitalism into the education system; somebody ends up with the short end of the deal, and that somebody is the next generation of budding bright minds.

The problem is the interpretation. Why is it that studies avoid child traumatic events that they never spoke about because they believe they will be in danger by their parents. From my personal experience, it can limit a kids beliefs about themselves and into adulthood. They think the problem is themselves and labeling them with certain disorders does a injustice to our future leaders. We know all the information needed, it's the perspective we are lacking. Money is not going to solve the problem, it's having a human to human conversation asking questions and making it clear "we got their back." It's a lot of emotional work but it must be done.

A study with a small sample size and questionable statistical validity, which does little but provide additional fodder for social justice workers. But it meets the definition of politically correct, which seems to be all that's necessary.

Reprinted with permission of MIT News