![\"Miners](\"\/\/media.nature.com\/w800\/magazine-assets\/d41586-019-03171-6\/d41586-019-03171-6_17288554.jpg\")
<\/div>\n<\/div>In former UK coal mining areas, genetic variants are linked with spending less time in school.<\/span>Credit: Roger Tiley\/Alamy<\/p>\n<\/figcaption><\/figure>\n <\/p>\n <\/p>\n The deep coal mine at the Yorkshire village of Kellingley closed in 2015 \u2014 the last of more than 1,000 such pits that once drove British industry. As the mines closed, the jobs went with them. Faced with economic and social decline, many people who could moved away.<\/p>\n Geneticist Abdel Abdellaoui has never been to Kellingley or any of the United Kingdom\u2019s other former coal-mining regions. But he has found something surprising about the towns and their inhabitants. His research shows that the DNA in these districts is flecked with disadvantage1<\/a><\/sup>, just as the coal seams once threaded through the ground.<\/p>\n By looking at the genomes of people living in former coal-mining areas, he has found genetic signatures associated with spending fewer years at school compared with people outside those areas, and \u2014 at weaker significance levels \u2014 variants that correlate with lower socio-economic status. Some genetic variants even correlate with political persuasion and whether or not communities voted to leave the European Union in the 2016 Brexit referendum.<\/p>\n Abdellaoui, who works at the University of Amsterdam in the Netherlands, acknowledges that he is venturing onto politically charged ground. \u201cI try to understand human genetic variation and this is what I run into,\u201d he says.<\/p>\n The study1<\/sup>\u00a0\u2014\u00a0published this week in\u00a0Nature Human Behaviour<\/i><\/a>\u00a0\u2014 is a high-profile example of an emerging trend: using huge amounts of data and computing power to uncover genetic contributions to complex social traits. Studies published in the past decade have examined genetic variants linked to aggression,\u00a0same-sex sexual behaviour<\/a>, well-being and antisocial behaviours, as well as the tendency to drink and smoke. In doing such science, geneticists are heading for controversial territory. They have even been accused of \u201copening a new door to eugenics\u201d, according to\u00a0the title of a 2018\u00a0MIT Technology Review<\/i>\u00a0article<\/a>\u00a0by science historian Nathaniel Comfort2<\/a><\/sup>.<\/p>\n To the geneticists and social scientists doing this work, the results offer a useful and important guide to the relative contributions of nature and nurture to specific behavioural traits \u2014 just as genetic analysis can already highlight people who have an increased risk of cancer or heart disease. The approach could, for example, improve understanding of how the environment affects complex traits, and so offer a way to intervene to improve areas such as public education.<\/p>\n \u201cIt is super-exciting,\u201d says Philipp Koellinger, a genoeconomist at Vrije University Amsterdam in the Netherlands. \u201cIt gives us better and more-precise ways for scientists to answer questions they have been interested in for a long time.\u201d<\/p>\n Caveats abound. The genetic contribution to any behavioural trait is relatively small and easily swamped by the influence of the environment. The studies can reveal only whether someone is likely to have a certain trait, and cannot predict the qualities of any one individual. Most scientists are quick to point out why they do this work \u2014 to establish what role, if any, genetics has in behaviour \u2014 and to lay out its limitations.<\/p>\n But not everyone is listening: already, some companies see a market in reading DNA like a fortune-teller reads tea leaves. \u201cThat stuff totally gives me the shivers. But it\u2019s happening,\u201d Koellinger says.<\/p>\n Critics charge that the ethical and societal risks of acting on such information are too great. \u201cOne of the main concerns is not so much the study of genomics, but how are we going to use it,\u201d says Maya Sabatello, a bioethicist at Columbia University in New York City. \u201cWho\u2019s going to benefit? Who\u2019s not going to benefit? We live in a very unequal society and this is a major challenge.\u201d<\/p>\n <\/p>\n Strength in numbers<\/b><\/p>\n For decades, geneticists assumed that most traits were governed by just a handful of genes \u2014 whether it was a relatively simple one such as height, or something as complex as antisocial behaviour. But as the sample sizes swelled, researchers began to find hundreds of variants that each have a relatively small effect on a trait. These projects \u2014 known as genome-wide association studies (GWAS) \u2014 build up a picture of which DNA letters vary from person to person (called single nucleotide polymorphisms, or SNPs), which variants are most common in people with a given trait and how much of the difference between individuals these SNP patterns represent.<\/p>\n Adding up the contributions made by all these spots on the genome gives researchers a measure of the importance of genetics to a trait, known as a polygenic score. For height, which is known to have a strong genetic influence, GWAS show that\u00a0variants can together account for 20% of the variation<\/a>.<\/p>\n As studies into physiology and disease piled up, scientists began to wonder whether the methods would work on social and psychological attributes.<\/p>\n For some complex traits, such as social isolation, researchers have found only a weak influence; one study3<\/a><\/sup>\u00a0noted that heritability for that trait hovers at 4%. But for others, the signal from genetics studies has blossomed from initially feeble to surprisingly strong. In 2013, a large group of researchers working under the umbrella name The Social Science Genetic Association Consortium (SSGAC) reported the first GWAS of educational attainment4<\/a><\/sup>, defined as years of schooling. The study found three SNPs that together could explain a meagre 2% of the variation in years of education. But then, a 2016 repeat by the same consortium using a sample that included almost 300,000 people \u2014 more than double the number in the 2013 study \u2014 found 74 SNPs that could explain 3.2% of the variation5<\/a><\/sup>. When the consortium combined data from 1.1 million people, they discovered more than 1,200 SNPs that together accounted for 11\u201313% of the variation6<\/a><\/sup>. That means the genes for educational attainment can explain about as much variation in a child\u2019s time in education as their family\u2019s socio-economic status can. \u201cI think that\u2019s really quite remarkable,\u201d says Tim Morris, an epidemiologist at the University of Bristol, UK.<\/p>\n <\/p>\n Graduating students at the University of Sheffield, UK. Genetic signatures linked to spending more \u2014 or fewer \u2014 years in school appear to cluster in geographic regions.<\/span>Credit: Roy Childs\/Alamy<\/p>\n<\/figcaption><\/figure>\n <\/p>\n <\/p>\n Beyond education, researchers have examined other socially shaped traits. In 2016, for instance, the SSGAC published a GWAS of almost 300,000 people and identified 3 SNPs associated with self-reported measures of well-being7<\/a><\/sup>. And in 2017, a weak genetic signature for antisocial behaviour showed up in a GWAS of a group of 6,200 Finnish prisoners8<\/a><\/sup>. Neither study produced a polygenic score, but researchers expect scores for these traits will emerge as sample sizes continue to grow.<\/p>\n The growing power of GWAS inspired Abdellaoui to ask a different question: how do social traits such as educational attainment vary across a country? To find out, he and his team dug into the UK Biobank data set, which holds blood and tissue samples and survey responses for almost 450,000 people and cross-references the information to medical data such as hospital admissions.<\/p>\n The team looked at previous studies to amass a list of 33 health and behavioural traits and the genetic variants that influence them, adding up the contribution of each variant to get a polygenic score. The researchers then investigated the UK Biobank samples to see whether these genotypes differed across the United Kingdom. They first discounted genetic variation caused by historical regional differences in ancestry, throwing out variants that are common because of shared ancestry rather than because they govern a trait. Then they could see which traits still clustered into certain regions. For some traits \u2014 caffeine consumption, for example \u2014 there was no regional difference. But for others, such as educational attainment, the difference was significant. The researchers found that people living in former coal-mining regions had, on average, fewer genetic variants that correlated with staying in school longer or with going on to higher education1<\/a><\/sup>.<\/p>\n Peter Visscher, a geneticist at the University of Queensland in Australia who worked on the study, says it\u2019s not clear what underlying biology the genetic patterns identified represent. \u201cI see that as a proxy for genes to do with intelligence and maybe perseverance, and maybe a bit of risk-taking.\u201d<\/p>\n Abdellaoui stresses that what they have produced is more description than explanation. \u201cThere are a whole bunch of variables that are clustering in the lower economic areas, but it\u2019s very difficult to say anything about directions of causality.\u201d<\/p>\n The researchers think the regional difference is down to the migration of more-educated people to richer areas that offer them jobs, leaving behind people who have genetic signatures linked to spending less time in school. This social stratification could become more marked over time, they say. \u201cIf that goes on for multiple generations, then for the sort of social inequalities already there, you run the risk of increasing those inequalities on a biological level,\u201d says Abdellaoui.<\/p>\n The researchers found the same geographic pattern for other traits, but the relationships were weaker. Genotypes known to be strongly associated with lower socio-economic status and lower cognitive ability were found more often in the poorer areas. These genotypes, the scientists reported, were associated with people\u2019s political views. Those in coal-mining areas had more genetic variants linked to lower socio-economic status, and were also more likely to vote for the left-wing Labour party or the right-wing UK Independence Party. Individuals were also more likely to have voted for the United Kingdom to leave the EU in the Brexit referendum. Abdellaoui says this does not mean that someone is genetically predisposed to vote in a certain way.<\/p>\n Other researchers in the field agree with this caution. \u201cOverall I like the paper and think that they\u2019ve done a good job with it,\u201d says Morris. \u201cMy main fear is that these results will be over-interpreted. They are informative descriptive statistics, but descriptive nonetheless.\u201d He also notes the UK Biobank data are \u201cextremely selective\u201d and not likely to fully represent the populations of the former coal-mining regions. \u201cFor the regional results, these really must be interpreted with care.\u201d<\/p>\n The results of this kind of study are based on associations, and must be presented very carefully to prevent suggestions that a person\u2019s genes determine their outcomes, says Daniel Benjamin, a behavioural economist at the University of Southern California in Los Angeles. He is wary of comparisons between his field and the spectre of eugenics, an idea from the beginning of the twentieth century that people seen as having \u2018inferior\u2019 genes should be prevented from having children. \u201cThose of us who do work in this area have an ethical obligation, and that ethical obligation is even stronger in the case of the genetics of behaviour because of past terrible misinterpretations and horrible consequences,\u201d he says.<\/p>\n One of the biggest sources of confusion is what a polygenic score actually shows about the contributions of nature and nurture, Benjamin says. \u201cPeople have a really hard time understanding that genes don\u2019t determine behaviour.\u201d<\/p>\n Abdellaoui says of his UK study: \u201cWe are in no way suggesting the genes are the sole determinant of someone\u2019s educational outcome. It\u2019s a combination of environmental and genetic effects.\u201d<\/p>\n <\/p>\n Genetics in the classroom<\/b><\/p>\n Another disclaimer is that polygenic scores represent the \u2018risk\u2019 of having a particular trait, and don\u2019t necessarily suggest that genetics is a major factor in behaviour. For instance, the scores cannot foretell that one individual will definitely graduate from university and another will quit school aged 16. \u201cI don\u2019t think that polygenic scores are at the level of predictive ability that would allow you to make those kinds of individual judgements with any degree of certainty,\u201d says Paige Harden, a psychologist at the University of Texas at Austin.<\/p>\n When Benjamin and his team put together the most recent GWAS on education6<\/a><\/sup>, his team released an accompanying 20-page list of frequently asked questions to explain the study\u2019s motives, which made clear that the scientists thought there were no implications for education policy. Not everyone is so cautious, says Morris. \u201cThere are quite a few academic papers coming out that can\u2019t resist a final sentence right at the end, along the lines of \u2018the DNA revolution is coming and genes will soon be useful for predicting education\u2019, which I think is quite irresponsible,\u201d he says. He wants such papers to include more context \u2014 for example, pointing out that existing information such as a student\u2019s previous attainment can already do a better job of predicting their future performance than a polygenic score can.<\/p>\n A working group announced earlier this month by bioethics think tank The Hastings Center in Garrison, New York, plans to examine the field and advise researchers and stakeholders on how to conduct and talk about the work (see\u00a0go.nature.com\/2vtbpey<\/a>).<\/p>\n But others are less guarded. They argue that genetic screens of behaviour and cognitive ability could help children as young as three to fare better at school. \u201cIt can\u2019t be right for education to continue to ignore genetic influence, because it\u2019s far and away the most important source of individual differences,\u201d says Robert Plomin, a psychologist at King\u2019s College London, who is one of the more bullish voices in the debate and whose interpretations of the studies are controversial.<\/p>\n Sabatello, the bioethicist, predicts that the first applications will be in specialist education, such as for cases in which the parents of children with conditions such as attention deficit hyperactivity disorder (ADHD), autism spectrum disorder or dyslexia could use genotypes as evidence to demand a different approach for their child. \u201cParents want the genomic information to persuade authorities or educational entities that their kids need the specialist intervention.\u201d<\/p>\n At the moment, there are no reliable polygenic scores to assess the contribution of genes to these conditions, but large-scale studies, more powerful than those done before, including a major GWAS currently under way for ADHD, could produce them in the future.<\/p>\n Although the focus on identifying and helping children with extra educational needs might sound altruistic, it, too, has a troubling historical precedent. Intelligence tests, which were first developed at the beginning of the twentieth century to pick out children who could benefit from extra attention, quickly became used to reinforce discrimination against minority populations or institutionalize children deemed to be \u2018feeble-minded\u2019.<\/p>\n \u201cMany teachers are worried that trying to use genetics as a tool in education could potentially be misused to validate race and class-based differences,\u201d says Daphne Martschenko, who has just finished a PhD at the University of Cambridge, UK, that investigated attitudes in education to genetics.<\/p>\n In fact, because GWAS are done mostly using data from people of European ancestry, this could make the results less applicable for different ethnic groups. \u201cA real pragmatic challenge is that we don\u2019t have good genetic indicators for children of colour,\u201d Harden says.<\/p>\n Morris thinks that this could compound existing inequality in education. \u201cIf you can\u2019t do something for everyone in the system, then you can\u2019t do it.\u201d<\/p>\n <\/p>\n Responsible research<\/b><\/p>\n Many in the field agree that the most useful application of these results will be to allow better-quality research into environmental \u2014 not genetic \u2014 influences on complex behavioural traits, by taking out the influence of genetics while studying some other factor. \u201cIt\u2019s an unsexy thing to talk about,\u201d says Harden, \u201cbut a better idea is using genetics as a control variable to work out what actually works to improve learning.\u201d<\/p>\n Researchers could include children with similar polygenic scores in both the control and test groups when trialling an intervention, for instance.<\/p>\n The results could also help scientists to probe whether the effects of genetics depend on an individual\u2019s environment \u2014 whether certain gene variants kick in only under some circumstances. And more-sophisticated genetic studies could unpick the importance of something called genetic nurture, in which environmental influences are misidentified as genetic. This could be the case with education, because well-educated parents both pass on their genes and are more likely to contribute indirectly by encouraging their children\u2019s schooling9<\/a><\/sup>.<\/p>\n The priority for most researchers in this field is to do more and bigger studies, to produce ever-stronger signals and tackle different traits such as income and social withdrawal. Meanwhile, those at the educational coalface don\u2019t need insight from genetics to improve outcomes, says Sabatello. \u201cWe need to look at the environment. Children who are hungry can\u2019t study. We don\u2019t need to have their genes for that.\u201d<\/p>\n <\/p>\n <\/p>\n<\/div>\n <\/p>\n <\/p>\n <\/p>\n (\uc6d0\ubb38: \uc5ec\uae30<\/a>\ub97c \ud074\ub9ad\ud558\uc138\uc694~)<\/p>\n <\/p>\n <\/p>\n <\/p>\n","protected":false},"excerpt":{"rendered":"![\"University](\"\/\/media.nature.com\/w800\/magazine-assets\/d41586-019-03171-6\/d41586-019-03171-6_17288550.jpg\")
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