December 11, 2013

The Guardian: "Genetics accounts for more than half of variation in exam results"

From The Guardian:
Genetics accounts for more than half of variation in exam results 
Environment, including home and school life, is a less important factor in pupils' GCSE results than genes, study suggests 
Differences in children's exam results at secondary school owe more to genetics than teachers, schools or the family environment, according to a study published yesterday. 
The research drew on the exam scores of more than 11,000 16-year-olds who sat GCSEs at the end of their secondary school education. In the compulsory core subjects of English, maths and science, genetics accounted for on average 58% of the differences in scores that children achieved. 
Grades in the sciences, such as physics, biology and chemistry, were more heritable than those in humanities subjects, such as art and music, at 58% and 42% respectively.

(58% + 42%) / 2 = 50%

Back when I got seriously interested in the human sciences, I developed a personal rule of thumb that nature and nurture tend to come out about fifty-fifty in importance. The heredity glass and the environment glass are generally both about half full and half empty.

Only wild-eyed extremists like me think that way, however.

Responsible moderates know that the nurture glass must be 100% full, and that anybody who points out that all the evidence suggests reality is more complicated must some kind of Nazi who is anti-Science.
The findings do not mean that children's performance at school is determined by their genes, or that schools and the child's environment have no influence. The overall effect of a child's environment – including their home and school life – accounted for 36% of the variation seen in students' exam scores across all subjects, the study found.

And there is considerable restriction of range in environment. This British dataset probably doesn't include many environments like Romanian orphanages or Dalit compounds on the Ganges.
"The question we are asking is why do children differ in their GCSE scores? People immediately think it's schools. But if schools accounted for all the variance, then children in one classroom would all be the same," said Robert Plomin, an expert in behavioural genetics who led the study at King's College London. 
To tease out the genetic contribution to children's school grades, the researchers studied GCSE scores of identical twins (who share 100% of their genes) and non-identical twins (who share on average half of the genes that normally vary between people). Both groups share their environments to a similar extent. 
Comparing the twins' exam scores allowed the scientists to work out how much of the variation was down to genetics, and how much to environment. For example, when identical twins get different GCSE scores, the cause cannot be genetic, so it must be what scientists call "non-shared environment" effects – such as the better student having a better teacher. 
A child's performance is influenced, but not set, by their DNA. While one child may excel, their identical twin may not. But taking an average over the population studied, around half of the variation in GCSE scores was due to genetics, Plomin found. Details of the study appear in the journal, Plos One. 
Writing in the journal, the authors point out that genetics emerges as such a strong influence on exam scores because the schooling system aims to give all children the same education. The more school and other factors are made equal, the more genetic differences come to the fore in children's performance. The same situation would happen if everyone had a healthy diet: differences in bodyweight would be more down to genetic variation, instead of being dominated by lifestyle. 
Plomin said one message from the study was that differences in children's performance were not merely down to effort. "Some children find it easier to learn than others do, and I think it's appetite as much as aptitude," he said. 
"There is a motivation, maybe because you like to do what you are good at." 
Genetics, he said, caused people to create, select and modify their environment, and so nature drives nurture, which in turn reinforces nature. A child with a gift for maths seeks friends who like maths. A child who learns to read easily might join a book club, and work through books on the shelves at home. 
Michael Reiss, professor of science education at the Institute of Education in London, said that while genetics undoubtedly plays a role in educational performance, the information might not be very useful. "Some people have to wear glasses because of genetic defects, and other people wear them for reasons that have nothing to do with genetics. As long as you are wearing glasses in school, it doesn't matter at all. The genetics is utterly irrelevant," he said.

But not for being a major league baseball hitter, apparently.
In the past 10 years, programmes have been developed that help children who have fallen behind with their reading to catch up. The programme does not rely on genetics, but focuses on the particular problems the children have in reading. "It doesn't matter if you're teaching maths, rowing or the trombone. A good teacher is very sensitive to the individual needs of the learner, and I don't think the genetics is going to help very much with that," Reiss said. 
Plomin said that educational performance could be affected by thousands of genes, each of which has a minuscule effect. Finding them will be tough, but would allow scientists to work out which gene variants affect performance in different subject areas. 
That might produce problems of its own though. "The worry is that parents, teachers and children themselves start thinking 'It's not worth my while trying, I don't have the genes for it', but that's false logic. The big problem is equating genetics with determinism. It's a very powerful [misconception] and difficult to shift," said Reiss. 
Plomin believes that education might be improved by enlarging schools so they have enough resources to offer children a greater range of subjects and activities, so each can find out what they are good at.

That was pretty much the conclusion of post-Sputnik reassessment of American education: we need giant consolidated high schools for tracking purposes (which also have really good football teams)! And then, after awhile, there was a new fad for "small learning academies," which Bill Gates sank $2 billion into, before declaring it all wasted.
"Education is still focused on a one-size-fits-all approach and if genetics tells us anything it's that children are different in how easily they learn and what they like to learn. Forcing them into this one academic approach is going to make some children confront failure a lot and it doesn't seem a wise approach. It ought to be more personalised," he said. 
"These things are as heritable as anything in behaviour, and yet when you look in education or in educational textbooks for teachers there is nothing on genetics. It cannot be right that there's this complete disconnect between what we know and what we do."

25 comments:

Thursday said...

But, of course, remember that "environment" is not the same as "social environment." "Environment" includes a lot of physiological randomness.

Anonymous said...

What I've never seen explained in any specifics is whether for particular individuals genes may account for a lot more than 50%; for others, a lot less. These are population averages, after all. What is the range of large individual variation that might be
seen in, say, three or four of the subjects in an experimental group of, say, 100??

bleeding-edge bloggers said...

Steve, did you really just prove that the sum of all percentages from a population is 100%

jgress said...

Whoa, since when has the genetic basis of academic ability been acceptable to publish in teh Grauniad?

Anonymous said...

if environmental factors contribute 50%, and given that our elites are better programmed for success than ever at their prep schools, trips abroad, baby eisntein tapes etc then are they smarter than ever? Is their output quality improving? are we seeing sharper thinking in any area? why not--the environmental inputs have clearly increased, at least, quantitatively

hbd chick said...

@jgress - "Whoa, since when has the genetic basis of academic ability been acceptable to publish in teh Grauniad?"

i know!

there's a lot of weird stuff going on in the u.k. lately -- they seem to be "getting" (finally admitting?) that there's such a thing as innate intelligence and that not everybody gets dealt the same hand wrt smarts.

don't mention it too much! don't make them self-conscious about it! let the momentum keep working.

(~_^)

JeremiahJohnbalaya said...

Steve, did you really just prove that the sum of all percentages from a population is 100%

No, he calculated the average of the two percentages. Values were the percent of X in two different group. They just happen to add to 100%. Reread the sentence in question to find X.

Anonymous said...

The system is self-correcting. As the average output converges in intelligence, outside shocks combined with groupthink precipitate a catestrophic event, with consequent mortality and diversion from the mean.

If average output diverges in intelligence, disparate mating and convergence to the mean dampen the divergence.

Neil Templeton

Anonymous said...

If I were to guess, I'd say those identical twin comparisons underestimate the contribution of genes b/c many identical twins have a psychological need to differentiate themselves from their twin. Thus, it's not uncommon for one of the twins to rebel.

And to the 'IQ/SAT tests are the holy grail' retorts I call b.s. If a high school student parties late into the night and smokes a joint to alleviate his hangover while on his commute to the SAT site, it will have an effect.

There is no washout effect b/c the twins are actively differentiating themselves--seeking polar opposites on their inborn predisposition range.

Anonymous said...

These vile hate facts have no place in the Guardian.

map said...

What do the Winklevoss twins have to do with Bitcoin?

Aaron Gross said...

The heredity glass and the environment glass are generally both about half full and half empty.

Only wild-eyed extremists like me think that way, however.

Responsible moderates know that the nurture glass must be 100% full....


That's insane. Maybe it was true about twenty years ago, but now the consensus is that the heritability of lots of psychological traits is around 50%. You read the New York Times and I don't, but every recent NYT article I've read on the topic follows the consensus view, that traits like IQ, for example, are substantially heritable.

I'll bet it would be hard to find any NYT articles (I'm not talking about op-eds) that take the view that you attribute to "moderates." Your own "wild-eyed extremist" view is held practically unanimously among the liberal elite, at least the media elite.

Of course it goes without saying, but has to be said anyway to preempt stupid objections, that the heritability estimated here is within-population heritability, not between-population "heritability."

jody said...

rowdy roddy piper alert. wonder what kind of name reiss is...

just kidding. i know it's a jewish name. there's a boxing referee, jack reiss, and his preference in boxing matches is pretty clear.

what's interesting from wikipedia is that half jewish michael reiss does not only not consider himself jewish, but is in fact an anglican priest.

nature over nurture i suppose, eh mike? he's a living embodiment of the reality which he denounces. he just can't keep that reflexive knee jerk reaction to any genetic talk at bay, no matter how culturally de-jewishified he is. he has to come flying in and denounce any idea that genes might matter in brainpower. he has to reassure the reader that possible nazis like robert plomin have got this stuff exactly wrong and have no idea what they're talking about.

the half jewish, not culturally jewish at all, anglican priest, who acts exactly like a left wing jew when certain topics come up. he proves plomin's point.

Anonymous said...

Okay, something funny's going on here. This is the Gruniad - what kind of waters are being tested? Because there is no way this would be allowed - maybe the results, and the differences in results, are getting too politically hot to explain away, so they need to set the bar for explaining that hey, it's not their fault.

(And as someone who thinks that their education system, independent of things like cognitive ability and race, has some severe problems, that does my head in.)

Steve Sailer said...

Responsible moderates know that the nurture glass must be 100% full....

"That's insane. Maybe it was true about twenty years ago, but now the consensus is that the heritability of lots of psychological traits is around 50%. You read the New York Times and I don't, but every recent NYT article I've read on the topic follows the consensus view, that traits like IQ, for example, are substantially heritable."

Sure, but what about New York Times editorials, like the massive one yesterday about how white boys are hogging all the STEM learning? There's a massive disconnect between what the fine NYT Science section reports and the way people talk in the Editorial, Op-Ed, Education, National, Arts, and International pages.

Or just read the comments on article in the Guardian.

Jesus wept.

I'm a notoriously terrible person because I read the science articles in the New York Times and the Guardian and I fail to forget them as soon as I start reading the non-science articles in the New York Times and the Guardian.

Anonymous said...

http://gu.com/p/3y659/fb

somehow fitting

Aaron Gross said...

1) If the editorial is about white boys compared to others, then it's not about within-population heritability.

2) I specifically excluded editorials (well, op-eds) just to be safe, but I think they're probably consistent with the reporting. And I'm not just talking about science reporting either, like the article you cited here. The NYT writes stuff related to IQ that isn't straight science reporting, and those articles never (from what I've read) say that it's all environmental; they do often say that it's substantially heritable. That's the elite position. Granted, the masses who post comments often lag behind the elite.

3) Who said you're a terrible person because you say that lots of personality traits are about 50% heritable? Again, this is within-population heritability. I've seen lots of people write that you're a terrible person, but never because of that.

Last word is yours, by the way.

Steve Sailer said...

At least the schizophrenic signing gibberish was quiet instead of honking on a vuvuzela.

sunbeam said...

All these twin studies.

But no one ever does it epic style.

By that I mean take one half of an infant pair that you are reasonably confident will have above average intelligence. Maybe one of those Galtons or Darwins or something.

Then put that in a certain kind of environment.

Having the crew in Precious as parents. Or put them with the White family in deepest West Virginia.

Besides sorta replaying the plot of Tarzan, Lord of the Apes, I'd be curious as to how things turn out.

I ask this because I have a belief of sorts about social environments, which has survived all contact with this site.

Namely that certain genetic traits you have are unlikely to be expressed or nurtured in certain environments.

If Isaac Newton took his first toke on a joint at age 9, then started tweaking at age 12. If he has to worry about his street cred and looking like a hard man, if his first baby mama gets knocked up at age 14...

There ain't a whole lot of room in there for intellectual pursuits you know.

I was also tempted to throw in some stuff about brain differences with feral children. A quick wiki walk indicates that this is mostly a fictitious phenomena, though apparently some cases have been observed. I mean I could take John Von Neumann and make something all kinds of f*#%ked up if I have given little John to this girl's daddy to raise: http://en.wikipedia.org/wiki/Genie_%28feral_child%29

pat said...

You cite Michael Reiss as saying, "Some people have to wear glasses because of genetic defects, and other people wear them for reasons that have nothing to do with genetics. As long as you are wearing glasses in school, it doesn't matter at all. The genetics is utterly irrelevant,"

I stumbled into the genetics of myopia while I was researching The Tuskegee Airmen. Racial differences in eyesight is seldom noted in the press. Dr. Reiss seems to be innocent of the basic facts.

IQ and myopia are strongly correlated. East Asians and Ashkenazi Jews have much higher rates of wearing glasses than other groups. Black men in America have myopia rates when young only about half those of whites.

The reason is probably because the same genes that make your brain larger also make your eyes larger. A longer eyeball will focus the image in front of the retina, not on it.

This is not a rare and obscure 'genetic defect'. It is a widespread racial characteristic. It seems wearing glasses in the classroom is not irrelevant after all.

Albertosaurus

jgress said...

I imagine that, if I were a NYT-times reading liberal, I would accept that intelligence is partly heritable, but that talent is still evenly distributed across races and classes. I don't think that NYT science article breathed a word about IQ differences across race or class.

Anonymous said...

The Guardian are slowly but surely coming to terms with the science.

It's painful to see, but consider that thirty or forty years ago a Hans Eysenck was attacked and had lectures boycotted - he was pretty much an unperson to liberals for saying the same things.

But that won't happen to Plomin - for one thing students are far too worried about their careers to smash up lecture theatres.

Whether they'll be so accepting when it comes to group differences remains to be seen. I think not.

Luke Lea said...
This comment has been removed by the author.
Luke Lea said...

"Plomin believes that education might be improved by enlarging schools so they have enough resources to offer children a greater range of subjects and activities, so each can find out what they are good at."

This comports with my (original?) suggestion of a cafeteria-style curriculum in very large central high-schools, with a broad range of both academic and vocational courses available. The Student and his or her parents would be free to choose any course they think he might like to take (and should probably be free to drop without penalty those they later decide are not suitable for them). There might be minimal requirements -- basic arithmetic and the main facts of US and world history on the academic side an a few vocational courses like cooking and masonry (or some other "hard labor" industrial art) to remove the stigma now associated with vocational training; but beyond that it would be up to the students and their parents, not teachers and administrators, to design the educational program that seems best fitted to their aptitudes and desires.

Anonymous said...

"Some people have to get a grade handicap because of genetic defects, and other people have to for reasons that have nothing to do with genetics. As long as you are getting a handicap in school, it doesn't matter at all. The genetics is utterly irrelevant,"