Researchers have cast doubt on a widely-held belief that connects family income with cognitive development, according to a new study published in Proceedings of the National Academy of Sciences.
A popular theory holds that genes play a larger role in brain development for children from advantaged environments than in those from poorer backgrounds, especially in the United States.
But in the largest study to date using matched birth and school records, the researchers from Northwestern University, Stanford University and the University of Florida found family income won’t necessarily mitigate the effects of genetics on cognitive outcomes.
“While children from higher socio-economic status backgrounds have much better cognitive outcomes on average than those from lower socio-economic status households, genetics appear to matter just as much for both groups,” said Northwestern economist David Figlio, study lead author and dean of the School of Education and Social Policy. “Genes matter. Environment matters. But we find no evidence that the two interact.”
Some studies suggest that the difference in genetic influence between rich and poor families is particularly pronounced in the U.S., but the Florida data, which includes records of siblings and twins, calls this idea into question, the researchers said.
The finding mildly surprised Figlio, but he said it falls in line with his previous work published in American Economic Review, which indicated that heavier babies do better in school. In that study of Florida children, Figlio and his coauthors found that those who were heavier at birth scored higher on math and reading tests in the third to eighth grades, and that the relationship between birth weight and test scores is essentially the same for everybody.
“It’s definitely still true that, from the point of view of test scores, you’d rather be a tiny baby from a wealthy family than a big baby from a poor family,” said Figlio, faculty fellow at Northwestern’s Institute for Policy Research. “But birth weight matters, and it matters for everyone. It seems the same effect is at play here.”
A full understanding of how genes interact with the environment for cognition is more complex and elusive than previously supposed, the researchers said.
“Being able to say that ‘genes’ matter more for this group versus that group is appealing partly for its simplicity,” said study co-author Jeremy Freese of Stanford. “We suspect the truth is more complicated: Some genes may matter more in richer families and other genes may matter in poorer families. There’s no overall characterization.”
Freese emphasized that genetic differences do matter in cognitive development. “But we are still far from understanding how in any useful way,” he said. “Meanwhile, we know poor children face many social disadvantages, and there is much we can do to address those to help promote the flourishing of all children.”
In addition to Figlio and Freese, Krzysztof Karbownik of Northwestern University’s Institute for Policy Research and Jeffrey Roth of the University of Florida, Gainesville, coauthored the study.
Image & Story Credit: Northwestern University
more recommended stories
Adolescents’ well-being and learning during COVID-19 linked to psychological needs
Multi-country analysis highlights importance of experiencing.
Nature draws out a happy place for children
New study explores children's perception of.
A gender gap in negotiation emerges between boys and girls as early as age eight
Understood to persist between men and.
Fellow students improve grades
Peers personalities can influence your own.
A window into adolescence
Researchers study biological roots for adolescent.
How students learn from their mistakes
Researchers at University of Southern.
Schooling is critical for cognitive health throughout life
Quality schooling matters cognitively for later.
To improve students’ mental health, teach them to breathe
Resiliency training programs could be a.
Jobs for the boys: How children give voice to gender-stereotyped job roles
Children, and especially boys, show stronger.
Playtime with dad may improve children’s self-control
Children whose fathers make time to.