My Times column on genes, intelligence and selective schools:
The good news is you can save on school fees. A new study finds that selective schools add almost nothing to the exam results of students, because the advantages teenagers come out with are mainly ones they arrived with, and are for the most part genetic. The bad news is that this implies genetic stratification of society is happening, and more than we thought. But then that is bound to happen in a meritocracy. If you make everything else equal, differences will be increasingly determined by genes.
The new study comes with impeccable credentials, from a team led by Robert Plomin, a professor at King’s College London and the acknowledged leader in the genetics of intelligence. Co-authors include the researcher Emily Smith-Woolley and the prominent school reformer (and social media witch-hunt victim) Toby Young, whose father coined the word “meritocracy” 60 years ago.
It is no longer controversial that genes influence intelligence. Studies of twins repeatedly show that in typical western society, measures of general intelligence derived from IQ tests have about 30 per cent heritability (that is, 30 per cent of the variation between people can be explained by their genes) in childhood, 40 to 50 per cent in adolescence and 60 per cent in adulthood. This increasing heritability with age may appear paradoxical but it makes sense: adults are free to find their own intellectual level, whereas children can be forced by pushy parents and good schools, or by bad friends and bad schools, into seeming less like they really “are” deep down.
The politics of this are also paradoxical. The left has tended to downplay the role of genes in intelligence, while the right has welcomed it. Yet if you argue that nurture is everything and nature is nothing, then you effectively condemn people who went to poor schools to being second-rate and irredeemable; if you think nature matters, then it follows that there are gifted people in bad schools who the system should discover and rescue through affirmative action. Professor Plomin’s own talents were recognised after an IQ test: he came from a home with no books and neither parent went to university.
Likewise, when scientists began speculating about whether homosexuality had a genetic contribution, about 20 years ago, some commentators were surprised to realise that gay people generally liked the idea, because it implied that being gay was not a “choice” but inherent to who they were.
Transgender activists have also welcomed recent work implying a genetic contribution to transgender identity. It supports the notion “that transgender is not a choice but a way of being”, as one geneticist put it. The same switch to thinking that genetics tends to be on the side of the progressives has not yet occurred with respect to intelligence.
Knowing that genes matter is not the same as knowing which genes matter. For a long time it was impossible to match intelligence to any particular genes. That has changed thanks to the ability to detect the influence of many hundreds of genes, each of small effect, in large samples of genotyped people. The resulting “genome-wide polygenic scores” (GPS), are measures of which gene combinations are present. Those with a high score proved twice as likely to go on to university as those with low.
So it is now possible to see whether good schools get good results because of good teaching or good selection. The new study looked at a representative sample of 4,814 students in non-selective state schools, selective state schools (grammars) and selective private schools. The students in selective schools did better at GCSEs than those in comprehensives, as expected. But the scientists then compared the genes of the three groups, using the GPS scores that predict the number of years spent in education.
They found that three times as many students in the top tenth of the population on a GPS score went to a selective school compared with the bottom tenth. Once they controlled for factors involved in pupil selection, the variance in exam scores at age 16 explained by school type dropped from 7 per cent to less than 1 per cent. “These results show that genetic and exam differences between school types are primarily due to the heritable characteristics involved in pupil admission.”
Crikey. So all those talented Etonians were pretty talented to start with. I’m an underachiever, having gone to the same school as the last prime minister, the current foreign secretary, the Archbishop of Canterbury and recent winners of a Nobel prize for medicine (Sir John Gurdon) and an Oscar (Eddie Redmayne).
Of course, the genes involved in making somebody succeed in school may not directly determine intellect; they could somehow have caused the child’s parents to be more conscientious and read to them every night, or they could have affected the child’s appetite rather than aptitude for learning. And parents send their children to private schools for reasons other than educational achievement: to marinate their kids in a certain social set, say.
Genes cannot be wished away. As the Harvard geneticist David Reich said: “Well-meaning people who deny the possibility of substantial biological differences among human populations are digging themselves into an indefensible position, one that will not survive the onslaught of science.”
When it comes to gender, some sex differences are genetic; breasts and beards are not social constructs. It is harder to decide which sex differences in behaviour are derived from nature, but again the paradox of heritability provides a clue. Two psychologists last month published a paper showing that in countries where women are least discriminated against, women are most under-represented in science, technology, engineering and mathematics. The percentage of STEM graduates who are female is twice as high in Turkey, Algeria and Tunisia as in Finland, Sweden and Norway. It appears that the more freedom girls have, the less likely they are to choose STEM subjects.
Today we rightly try to make sure that any differential outcomes by sex, race or education are not caused by discrimination. But the result is that we will maximise the contribution of innate preferences and abilities instead. A perfectly meritocratic society would be one in which people who went to Oxford were genetically, not socially, advantaged.
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