When 10-year-old Nora from Oslo sat down to take her national school test, her score was shaped not only by the genes she inherited but also by the ones she didn’t—by the subtle, invisible hand of her parents’ DNA still guiding her life from the background. At the Institute of Science and Technology Austria (ISTA) in Klosterneuburg, Professor Matthew Robinson and postdoctoral researcher Ilse Krätschmer have, for the first time, disentangled how much of a child’s traits come from their own genes versus the environmental ripple of parental genetics—a phenomenon known as “genetic nurture.” Their groundbreaking study, published in Cell Genomics and conducted with Alexandra Havdahl of the Norwegian Institute of Public Health, analyzed data from 30,174 families across Norway and Estonia, revealing that the home environment shaped by parents’ genes can influence a child’s development nearly as much as the DNA the child actually carries.
For decades, genetic research has focused on direct inheritance—how a person’s traits reflect their own genome. But this new work shows that indirect forces matter profoundly. Parents’ genes influence everything from nutrition and emotional support to educational expectations, creating environments that shape outcomes like height, body weight, and academic performance. The team’s novel statistical method allowed them to separate these “genetic nurture” effects from direct genetic transmission—and even account for the tendency of genetically similar people (like tall individuals) to partner with one another, which can skew results.
The findings were striking: for height, 68% of genetic influence came from the child’s own DNA, while 32% stemmed from genetic nurture. For BMI, the split was 63% direct and 37% indirect. Most surprisingly, in school test performance, 58% of the genetic contribution came from the child’s own genes, and a full 42% from the environment shaped by parental genetics. This means that nearly half of what we might assume is “innate” academic ability is actually nurtured by conditions rooted in the parents’ DNA. The study also explored parent-of-origin effects—where certain genes behave differently depending on whether they come from the mother or father—but found these had minimal impact compared to genetic nurture.
These insights reshape how we understand human development. They suggest that improving environments—through better education, nutrition, and parenting support—can powerfully alter life outcomes, even within the framework of genetics. As Robinson puts it, “Genes don’t operate in a vacuum.” The implications extend to public health, education policy, and personalized medicine, offering a more nuanced view of how biology and environment intertwine across generations. With this new method, scientists can now explore these dynamics in mental health, chronic disease, and beyond—ushering in a more complete science of who we are, and how we got that way.