Growing up in the age of genomics

How will the latest findings in genetics affect the educational paths of children born in recent years?
Marvin Girbig, flickr.com, CC BY 2.0
Marvin Girbig, flickr.com, CC BY 2.0

How much of a child’s educational attainment is determined by her genes? New research is shedding light on variations in the genetic code that explain some of the differences in educational outcomes. But these findings also underline the huge role environment plays in shaping a child’s success or struggle in school.

Having recently become parents, my partner and I have entered a world that requires decisions we had never before had to consider. One question in particular looms large, and will probably continue to do so for the next few years: What can we do to help our daughter get the best education possible? Should we move to a different part of town with better schools? Or should we trust that we, her parents, have passed down to her the intellectual capacities that will allow her to succeed under practically any circumstances?

We have already done one thing, for better or worse: We have given her a mix of our genes. Our daughter is growing up in the age of genomics, which will add a new spin to the phenomenon of “blaming your parents”: “I inherited gene variant xy from you, thanks Mom and Dad!”

It is mind-boggling to imagine that our daughter may someday have her genetic make-up analyzed – as millions of people already have – and to think of how that knowledge may affect her life. It might help her choose a healthier lifestyle, as she takes into account whatever health risks she may have inherited. But might a DNA test also predict her chances of educational success?

A study published at the end of July 2018 has raised precisely that question: How much of a person’s potential for educational attainment is inherited, and how much is shaped by the environment? In this study, the Social Science Genetics Association Consortium (SSGAC) discovered gene variants in the human genome that correlate with educational attainment. Does that mean that our daughter’s educational destiny is already fixed, immutably written in her genome?

This topic is a minefield: Throughout human history, discrimination has too often been justified with arguments referencing genetic differences. So it is important to understand what the SSGAC study and others can – and cannot – tell us about a genetic predisposition to success in school.

“It is important to understand what recent studies can – and cannot – tell us about a genetic predisposition to success in school.”

A bit of background: Our genomes consist of a sequence of the letters A, G, C and T – which stand for the nucleotide bases in our DNA – for a total of over 3 billion letters. This equals the letter count of 585 copies of all seven Harry Potter books. Most of the sequence is the same for all humans, but in about 10 million positions in this code, one individual will differ from another: you may have an A where your neighbor has a G.

We’ll call these variable letters “variations”. By comparing thousands and thousands of genomes, scientists are trying to identify variations that are associated with an increased or decreased risk of developing a certain disease. For example, they are seeking to identify the small number of variations, out of a total of 10 million, that may make you more prone to developing heart disease or Alzheimer’s. This type of study is called a “genome-wide association study” or GWAS.

“Genes are a relatively poor predictor of educational success.”

Such studies can provide important insights into the inner workings of a disease and thus help to create new therapies. They may also reveal which individuals might profit from preventive measures.  But GWAS seek to understand not only diseases, but also the genetic basis of any other human trait, such as height.

Our educational destiny is not dictated by our genes

Educational attainment was one of the first areas social scientists focused on when they began to use GWAS to study the heritability of behavior. In 2013, a comparison of the genetic sequence of roughly 100,000 individuals revealed three variants that appeared to be connected – albeit weakly – to educational success. Five years later, with genomic data from 1,1 million individuals to compare, the SSGAC was now able to identify 1,271 variants that appear to be associated with educational attainment as measured by the number of years of completed education.

On its own, each variation has almost no impact, but the picture is very different when we look at all these variations taken together. The researchers used them to calculate a score. The more variations you have that are favorable to education, the higher your score. And this score explains about 11 % of the differences in educational attainment across the population. This is quite high from a geneticist’s point of view, but ultimately, it means that genes are a relatively poor predictor of educational success. So most of the explanation for why some individuals complete more years of education than others can probably be found in environmental and other non-genetic factors.

“Identifying these genetic variations is important, as this can help to disentangle the effects of genes and environment.”

Even before this study, we knew from other research that genes play only a minor role in a child’s success in school. So why go to the trouble of analyzing genomic data from over a million people? Will the identification of these 1,271 variations help to provide a confident prediction of a child’s predisposition for educational success or struggle?

The simple answer is no. Given the many environmental variables that affect performance in school, it is impossible to predict an individual’s future based solely on that person’s genome. The SSGAC study shows that on average, individuals with the highest score are more likely to graduate from college than those with the lowest score. But any one individual may deviate enormously from that average.

“Future studies might reveal whether individuals with certain genetic variations profit more from specific educational interventions than from others.”

So our educational destiny is not dictated by our genes. But identifying these genetic variations is important, as this can help to disentangle the effects of genes and environment. Further study of these variations may help us gain a better understanding of the brain, shedding light on how environment shapes the way these genes play out to affect educational attainment. And in a more practical sense, future studies might reveal whether individuals with certain genetic variations profit more from specific educational interventions than from others.

As for the question we, as new parents, are facing, namely whether or not we should move to an area with better schools in the interest of ensuring our daughter’s educational success: This study doesn’t really give us any answers. Our child’s upbringing, friends, and teachers will all have a huge impact on her development. All we can do is provide support where it is needed, and make sure that she grows up in a safe environment in which her talents and potential can be fully realized.

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