August 24, 2011

"Double Inanity"

In Slate, Brian Palmer denounces 135 years of twin studies in "Double Inanity:"
The idea of using twins to study the heritability of traits was the brainchild of the 19th-century British intellectual Sir Francis Galton. He's not exactly the progenitor you might want for your scientific methods. Galton coined the term "eugenics" and was the inspiration for the push to manipulate human evolution through selective breeding. ...

Over the last few decades, Galton's older half-cousin Charles Darwin has been promoted from secular sainthood to his current role as the Jesus of Atheists. But, the rise of Darwininsm in prestige has not been an unmitigated blessing to the world, so Galton has come to play the role of scapegoat, or devil. Since Darwin, the secular redeemer, is, by definition, above sin, all sins associated with Darwinism must be the fault of the designated devil, Galton.

It's a very odd phenomenon, since the two kinsmen would otherwise seem so objectively similar, both by nature (both were grandsons of the famous Erasmus Darwin, who propagated a theory of evolution in the late 18th Century) and by mutual nurture. The younger man vastly admired the older man, and the elder came to be highly impressed with the younger.
Nearly five decades after Galton published "The History of Twins"—and more than 10 years after the word "gene" entered the lexicon—researchers in the 1920s "perfected" Galton's methods by comparing identical and fraternal twins and inferring heritability from the differences between the two. The twin study today is based on the same assumptions that were made back then. (As you may be aware, a lot has changed in the field of genetics over that time.) And despite numerous indications that these assumptions are deeply flawed, researchers continue to crank out new papers, probably in response to a public demand—both insatiable and inexplicable—for evidence that we're just like our parents. (If only Freud were alive today.) ... 
Twin studies rest on two fundamental assumptions: 1) Monozygotic twins are genetically identical, and 2) the world treats monozygotic and dizygotic twins equivalently (the so-called "equal environments assumption"). The first is demonstrably and absolutely untrue, while the second has never been proven. 
That identical twins do not, in fact, have identical DNA has been known for some time. The most well-studied difference between monozygotic twins derives from a genetic phenomenon known as copy number variations. Certain, lengthy strands of nucleotides appear more than once in the genome, and the frequency of these repetitions can vary from one twin to another. By some estimates, copy number variations compose nearly 30 percent of a person's genetic code. 
These repeats matter. More than 40 percent of the known copy number variations involve genes that affect human development, and there are strong indications they explain observed differences between monozygotic twins. For example, it's often the case that one identical twin will end up victimized by a genetically based disease like Parkinson's while the other does not. This is probably the result of variations in the number of copies of a certain piece of DNA. Copy number variations are also thought to play a role in autism spectrum disorder, schizophrenia, and ADHD, all of which can appear in only one member of a monozygotic twin pair (PDF). If copy number variations can affect discrete and diagnosable disorders, then why shouldn't they influence far more complex behaviors like your inclination to head to the polls on a Tuesday night in November? 
That's just the beginning of the genetic differences between monozygotic twins. As a result of mutations during development, about one in 10 human brain cells has more or less than the typical two copies of a chromosome. Identical twins also have different mitochondrial DNA, the genetic information stored in the cellar organelle responsible for processing glucose. Research suggests that mitochondrial DNA affects brain size among a host of other neurological traits.
Twin studies also rely on the false assumption that genetics are constant throughout one's lifetime. Mutations and environmental factors cause measurable changes to the genome as life progresses. Charney cites the example of exercise, which can accelerate the formation of new neurons and potentially increase genetic variation among individual brain cells. By the time a pair of twins reaches middle age, it's very difficult to make any assumptions whatsoever about the similarity of their genes.

To his credit, Matthew Yglesias smells a rat:
That doesn’t seem to me to follow. It’s still the case that identical twins are more genetically similar than other kinds of siblings. So if we have a study showing that identical twins are systematically more similar in some respect than non-identical twins, we’re still in possession of evidence about the influence of genetic similarity on behavioral similarity. 

One of his commenters gets to the heart of the problem.
I'd go further. The case where identical twins are truly identical is a floor, not a ceiling. If identical twins are so similar despite some "copy number" and "mtDNA" differences, well, think how much more they'd be similar if you took even those additional genetic differences away. Unless the guy thinks these residual differences are anti-correlated (instead of being uncorrelated) with any differences in environmental inputs - a fairly bizarre supposition - what he's really saying is that twin studies *understate* the impact of genes.

Palmer goes on:
The equal environments assumption is similarly questionable. As anyone who's ever seen a pair of toddler twins in matching sailor suits is surely aware, monozygotic twins do get special treatment. They are more likely than their dizygotic peers to be treated as "two of a kind" by family, friends, and teachers, which must increase their chances of developing similar behaviors. There have been numerous studies showing that dizygotic twins who look similar have more personality traits in common than those who are easily distinguishable.

First, that's why the holy grail of twin studies are identical twins raised apart studies. They are hard to find, but very interesting. Second, there's the good enough for government work angle -- if the question is, can we produce equality of results by social engineering equality of inputs, well, children of the same age raised in the same home at the same time are about as equal as we can expect any government program to get the environment.

47 comments:

Lugash said...

I am Lugash.

Off topic, Fat Boy Slim ups his share in the Times:

http://slatest.slate.com/posts/2011/08/24/carlos_slim_new_york_times_mexican_billionaire_boosts_stake_in_n.html

I am Lugsh.

Nanonymous said...

[Galton] He's not exactly the progenitor you might want for your scientific methods.

WTF? Who is Brian Palmer and why does he think that demonstrating such a profound ignorance is a good idea? Galton was an astonishingly talented guy and his contributions to science and statistics are varied and profound (meteorology, statistics, anthropology, evolution and heredity). Whether Brian Palmer likes it or not, the fact remains that Galton was progenitor of many scientific methods. (In fact, as long as scientific method itself is concerned, Galton was more more prominent than Darwin).

dearieme said...

Palmer is being seriously dim, for the reason identified by the commenter you cite.

Anonymous said...

So he's the evil cousin? I like it.

Anonymous said...

"That identical twins do not, in fact, have identical DNA has been known for some time. The most well-studied difference between monozygotic twins derives from a genetic phenomenon known as copy number variations. Certain, lengthy strands of nucleotides appear more than once in the genome, and the frequency of these repetitions can vary from one twin to another. By some estimates, copy number variations compose nearly 30 percent of a person's genetic code."

First, 'race is a myth' or 'race is a social construct', and now 'identical twins are a myth or social construct' since they are not TOTALLY identical down to the last molecule.
What will they be telling us next? There's more genetic variation between twins than between twins and non-twins(like the misleading notion that there's greater genetic variation within a race than between races--while true when we look at extreme individuals such a midget and giant, not true when we consider average members of the races in consideration)?

I guess the notion of 'identitical twin' has the psycho-social ring of 'homogeneous race', and so the very concept of 'identical' must be banished. So what should they be called? Diverse Twins?

AMac said...

> researchers in the 1920s "perfected" Galton's methods

Sneer quotes.

> evidence that we're just like our parents. (If only Freud were alive today.)

Same paragraph, sneer parentheses. Very innovative writing.

> Twin studies rest on two fundamental assumptions: 1) Monozygotic twins are genetically identical, and 2) the world treats monozygotic and dizygotic twins equivalently

In his Slate article, Palmer offers no citation for either sweeping assertion. He could have stated (1) more accurately as, "Monozygotic twins are genetically very, very similar to one another, exhibiting far, far closer similarity than any other pairs of humans."

"Demonstrably and absolutely untrue" -- that borders on misleading.

It's worth clicking on the links Palmer does supply. Most of them undermine his central thesis, rather than supporting it.

Perhaps this author is too dim to understand the point made by Yglesias' commenter ("The case where identical twins are truly identical is a floor, not a ceiling.") Or maybe he's so dismissive of his Slate audience that he doesn't care.

AMac said...

The comments at Slate are worth a scan. Palmer's article is getting the reception it deserves from >90% of those who wrote in.

EYE OF HORUS said...

Slate is the political equivalent of "Penthouse Letters" for Liberals. A column of fictional fantasy that correlates strongly with what the readers want to believe are true.
Conservatives should avoid it completely like they do for Penthouse. It is a fantasy world for Liberals and Liberals only. Anyone else would find it puerile, ridiculous and digusting...

Jeff said...

Does anyone else think that nearly every attack on genetics is just a preemptive action to combat the rise of incontrovertible evidence that intelligence is heritable? Since the black/white achievement gap in school and work is quite likely one of the top three social issues in the nation (abortion being another of the top 3) what else can explain an article that attempts to suggest twin studies are not really very useful?

sabril said...

This is one of the basic arguments against HBD which is used time and time again.

Basically, it boils down to this:

"Because your methods are not 100% perfect, your conclusions must be rejected 100%."

Of course, less controversial social research is generally not held to this high of a standard.

Anonymous said...

Your analysis of contemporary liberal mores-Darwin as Jesus, Galton as Lucifer is brilliant:Spot-on!

Anonymous said...

off topic, but

"In fact, a shocking 49 percent of all babies born in the U.S. are born to families receiving food supplements from the WIC program, according to Jean Daniel, spokesperson for the USDA."

http://abcnews.go.com/US/hunger-home-american-children-malnourished/story?id=14367230

Chief Seattle said...

I once asked Google if you have to be Jewish to write for Slate. I was surprised to only find two relevant responses.

It's sad to see the NYTimes headlines get ever closer to Slate's form-of-a-question snark.

Henry Harpending said...

The recent GWAS of IQ from Ian Deary's group should put an end right now to this issue. Take a half million SNPs, compute how related random pairs of people are, relate that to their IQ difference. Bingo.


"Genome-wide association studies establish that human
intelligence is highly heritable and polygenic", G Davies et al., Molecular Psychiatry 2011,1-10.

Charles Murray has a nice take on the paper at

http://blog.american.com/2011/08/the-debate-about-heritability-of-general-intelligence-radically-narrows/


Henry

Anonymous said...

What a feeble attempt at muddying the waters. Even the Slate audience can see through it.
Gilbert P.

TH said...

The equal environments assumption of twin studies has held up really well, suggesting that the fact that MZ twins may be treated more similarly than DZ twins is not causally relevant for IQ, personality, or other heritable traits.

Palmer does not understand that only similarities in trait-relevant environmental factors contribute to similarities between twins. For example, if MZ twins are more likely to share the habit of drinking orange juice than DZ twins, this does not mean that the IQs of MZ twins are more similar than those of DZ twins because they drink more orange juice, unless you can demonstrate that drinking orange juice influences your IQ.

The big mystery in behavioral genetics is in fact that it's really difficult to find any trait-relevant environmental factors, even though the environment clearly contributes to variation in most traits.

Anonymous said...

"Does anyone else think that nearly every attack on genetics is just a preemptive action to combat the rise of incontrovertible evidence that intelligence is heritable? Since the black/white achievement gap in school and work is quite likely one of the top three social issues in the nation (abortion being another of the top 3) what else can explain an article that attempts to suggest twin studies are not really very useful?"

Yes, I'm quite confident that that's what it is. Gould-ism might be a good word for it. The implications of intelligence heritability are so alarming to most people (especially liberals) that any means of discrediting this kind of research are acceptable.

Anonymous said...

I'm no great fan of conclusions drawn by guys like Galton. Though, given the chance, I'd probably be intent on strict management of the environment in relation to population genetics in a certain region. If you did this in a neutral way, treating it like an ecosystem that includes careers, parenting strategies, and responsibility toward family and community, I don't see any harm in doing the best with the material you've got. Of course immigration would get to be an important and controversial issue if we were to focus intently on how populations function internally and what might happen if you introduced other races/ethnicities into the mix.

So some dead white guy had some ideas about eugenics you find repulsive. Doesn't mean you can't use his studies for another purpose while remaining skeptical of what he thought were the implications.

I guess Palmer's on the team hoping that the US can elect a new people at any time for any reason while the existing citizenry not only allows itself to be replaced but even gets excited about it.

ben g said...

Relevant: http://www.gnxp.com/blog/2009/11/does-family-matter-for-adult-iq.php

Seperated twins are about 10% less similar than reared together twins by adulthood.

The Explainer said...

You know you really have to be a bad writer for the readers of Slate to rip on you in the comments section of such a politically correct attempt to discredit racists like Gaulton or twin studies researchers.

It looks like Brian Palmer was a Cornell English BA, a Yale JD and fell into journo after fleeing a 4yr stint at BigLaw.

Despite lacking any STEM background, Brian is a prolific writer of sexy superficial popsci fluff for Slate and the Wash Post with the telling email handle explainerbrian@gmail.com.

Palmer injects typical leftist slants like anti-Christianity into his frequent pieces. However, this seems secondary to finding sexy popsci angles to topical subjects. He writes like a cross between Cecil Adams/Straight Dope and the new PC and dumbed-down Scientifican American style.

This anti-twin study article was atypical of his fluffy popsci style. Brian waded a bit too deep into science he obviously does understand and exposed his irrational hatred of unclean/unPC thought/science more than usual here. Even Slate readers were offended by the result.

Francis D. said...

"Over the last few decades, Galton's older half-cousin Charles Darwin has been promoted from secular sainthood to his current roles as the Jesus of atheists."

You aren't joking. Universities and other liberal havens went absolutely insane a couple of years ago on the two hundredth anniversary of his B'day with bizarre celebrations, poems and plays. No other scientist, even Einstein, is treated with such fervor at anniversaries. Particularly bizarre to see liberals blessing an Anglo-Saxon man in this way. Evidently,giving a middle finger to the Christian Right trumps even race.

Nanonymous said...

Identical twins also have different mitochondrial DNA

No, they don't. Mitochondria are maternal and all children of the same mother have identical mDNA (mutations notwithstanding).

Anonymous said...

"In fact, a shocking 49 percent of all babies born in the U.S. are born to families receiving food supplements from the WIC program, according to Jean Daniel, spokesperson for the USDA."


Doesn't this just show that only idiots breed when they can't feed their kids?

Give the sluts jail time instead of food stamps and they will shut their legs fast enough.

Anonymous said...

One could, thinking outside the box, look forward to a time when the evidence of group differences in IQ, based on heritability, is so overwhelming that the Hard Left has to acknowledge it; I am convinced they will find other reasons to justify their policies of wealth redistribution and European dispossession.

These arguments will be based on 'fairness' and be centered on 'compensation' for the bad hand that nature has dealt them. This philosophy has a long tradition and will constitute a powerful exploitation of our endless capacity for reflexive guilt.

We should prepare ourselves. They can't lie forever, at least, they can't keep telling the same lies forever.

Anon.

Glaivester said...

I've just thought up a new symbol to use against the egalitarian fundamentalists.

It's sort of based on the Darwin fish, but it attacks the liberals' false god.

The Galton (In)equality Sign.

Anonymous said...

Interesting analogy regarding Darwin and Galton. The ironic thing though is that Galton was much closer philosophically to a contemporary atheist than his half-cousin Charles was. Galton could almost be considered a Victorian proto-atheist, the Richard Dawkins of his day, but Dawkins is more generally compared to a modern T.H. Huxley than Galton. This is because like Huxley he loves public debate.

The other thing I find amusing about the hatred directed at Sir Francis is that he was really the prototype of the modern day quantitative social scientist. This is something a lot of modern day social scientists like to think they are, but Galton was really model for all of them, although very few social scientists would acknowledge him as their progenitor. Galton was arguably the first experimental psychologist, the first forensic scientist, as well as one of first biological anthropologists. He also unlike virtually all social scientists today, made significant contributions to science, notably statistics and meteorology.

Nanonymous said...

giving a middle finger to the Christian Right trumps even race.

Part of the blame is with Christian Right by foolishly denying the obvious and incontrovertible. Funny how Christian Right and Atheist Left are mirror images of each other in their denials of evolution and HBD.

TGGP said...

Karl Smith gives an excellent response to Palmer.

Anonymous said...

"Funny how Christian Right and Atheist Left are mirror images of each other in their denials of evolution and HBD."

I don't share any of your ideas on what conclusions to reach regarding the obvious differences between populations on all kinds of measures. I don't believe the term IQ is precise enough for one though it is the major focus around here. I'm also a little skeptical about that term "evolution" unless by it you mean change more than a supposed move up the ladder to, say, transhumanism.

NOTA said...

The useful lesson here is one about human nature: when you want to believe something, even incredibly lame, silly arguments seem pretty convincing. The hard part of this lesson is seeing when you are letting lame arguments and bogus claims of fact convince you of something you really want to believe.

rob said...

Has anyone else noticed that leftists never call the dead white men and their ideas that they like discredited? Palmer was all 'paging Dr. Freud.' when 'paging Dr. Freud, whose ideas were all so silly that that they aren't even wrong, but are useful in our critiques to undermine your culture.' would have been far more accurate.

Often they want their early intellectuals judged on a much easier curve. They might concede that Darwin was wrong in many details and there was a whole lot of shit he didn't know, but got the framework right. Galton never gets off that easy. The phrenologists were wrong in details: they thought some functions were localized to the wrong areas of the brain. The were very right in the framework: brains are organs, one of the things they do is making thoughts, and some functions are localized. Turns out, you can't feel the size of someone's brain through his skull. But brain scans are pretty obviously cousins to phrenology.

That word, 'descredited,' I do not think it means what they think it means. To me, it means not true. To them, they get wonderful cognitive dissonance: Soliciting tall, attractive, athletic, good tempered Ivy league egg donors is simultaneously pointless and unfair the children of the rich a genetic leg up.

Their desperate grasping at epigenetics is hilarious, first their magic epigenetic inheritance works just like genetic inheritance, but you CAN'T CALL IT GENETIC! They forget that genes, at least in the Galton/Darwin sense, are units of inheritance, not a particular stretches of DNA, cuz they didn't know 'bout the DNA. Hell, people thought proteins could be the genetic material way back when. They never claim that racial differences in skin color are epigenetic, prolly because in layman's sense, they mean heritable.

rob said...

EYE OF HORUS, that's hilarious and true. I'm so stealing it!

It's very telling that none of the Slate commenters got the Darwin is to Galton as God is to ____.
(answer A: Devil) analogy. They haven't swallowed the red pill of biology. They'd be appalled at the thought of the preservation of favored races in the struggle for survival. They'd love group selection, since it doesn't jibe in their minds with capitalism or 'social Darwinism.' Then when they realize implications of group selection, run away like hell.

Funny how the nurturists always use height as their example of a trait that's influenced by environment and genetic variation, never skin color. We know there are environmental influences: that's why tanning beds make people tan. Yet black people are darker, and equalizing environments would most likely increase the racial difference.

Georgia Resident said...

What did Francis Galton ever do to Palmer to inspire his hatred, other than saying that stupid people shouldn't reproduce.

Maybe that has something to do with Palmer's intelligence or lack thereof...

Londoner said...

Slate writer yearns for Freud to return from the dead and bash the uppity goyim over the head with some good old-fashioned critique... I wonder if Brian Palmer thinks no one is able to make this kind of connection when they read his screed?

Of course identical twins creep out the kind of person who writes for Slate. They are living, breathing reminders of the fact that shared genes = shared interests, culture and destiny. Genes are racist. Families are racist. Twins are racist. (with apologies to Svigor)

Eugenick said...

I was banned on RichardDawkins.net for mentioning Darwin's beliefs about HBD (quotes from his books compiled at http://www.heretical.com/darwin/darwin4.html ).

Make no mistake about it: "Atheism" is no less of a religion than Christianity! Some Atheists WILL ban you rather than allow you to say bad things about their God Darwin, the same way Christians will ban you for bringing up God's wrathful and vengeful nature from the Old Testament.

Anonymous said...

"Funny how Christian Right and Atheist Left are mirror images of each other in their denials of evolution and HBD."


Except that they aren't.

The Christian Right denies evolution as a basis for the origin of life, species etc. They do not deny that which has been proved, and is demonstrably true in the here and now, selection and heritability.

The Atheist Left accedes to the theory that all life has a spontaneous origin. However, they deny what has been proved in the here and now, selection and heritability.

Regardless of one's position on origins (which none of us has personally witnessed) disbelieving the demonstrably true is a more egregious failing.

Anonymous said...

Just anecdotal evidence... I used to babysit twin girls. I hadn't thought about it at the time, but I realize I really did treat them as one and the same. Didn't really think about it till it was brought up. Their personalities seemed interchangeable to me, and I treated them that way.
I guess dealing with 5 year old twins, I was just interested in keeping them from being a major pain in the ass, which they were always on the verge of being at all times. Under that kind of pressure, I didn't really think about treating them as individuals. I was only interested in keeping the peace.

Anonymous said...

If Eugenics is so bad, how come liberal elites practice it all the time? It's not like Jewish and wasp liberals are marrying low IQ janitors or lawn-mowers. While they condemn and oppose it on society at large, they practice it within their own communities.

On the other hand, open borders is a kind of anti-white eugenics, or eugenocidics carried out on a macro-level. Also, since liberals say race-mixing will make us 'more beautiful, more intelligent, wiser, etc', the underlying agenda is also to 'improve the race'.

The current agenda of genetic Eurocide is to mix up the races so that the mixed-race masses will be too confused to ever rise up against the elite.
Look at Mexico. If it were 5% white at top and 95% pure blooded Indian on the bottom, whites would be toast. Indians would unite as Asian-Indians eventually did against the Brits.
It was mestizo-ization that led to confusion among the masses, which had allowed the white elites to rule for a long long time.

So, if your people, as conquerors, will be the racial majority in the new nation, the dominant people need not mix with the natives. Whites in Australia mostly didn't mix with natives, but they outnumber the Aboriginals by far.
But if, as conquerors, your people are gonna be the minority, it helps to rape a lot of native women and create a middle-race, like the mestizos in Mexico or mulattos in Brazil.

Georgia Resident said...

That's something Palmer may have wanted to think more carefully about before writing. Yes, identical twins are not perfectly genetically identical. But they are still more related than fraternal twins, and have more homogeneity in traits. What matters isn't the upper limit of genetic similarity between MZ twins, but the ability of greater genetic similarity to predict greater homogeneity of phenotype.

Still, it's funny to see a pompous fool inadvertently embarrass himself. He should be the poster child for the modern left.

Anonymous said...

"But if, as conquerors, your people are gonna be the minority, it helps to rape a lot of native women and create a middle-race, like the mestizos in Mexico or mulattos in Brazil."


Oh, please, no need for rape. Low status women don't run in terror from high status males. Duh.

Anonymous said...

If Eugenics is so bad, how come liberal elites practice it all the time? It's not like Jewish and wasp liberals are marrying low IQ janitors or lawn-mowers. While they condemn and oppose it on society at large, they practice it within their own communities.


Oh, they are more than willing to practice on others, too. Among ob/gyns, Jews, females and irreligious are most likely to perform abortions, while evangelicals and catholics are the least likely.

Libs are totally on board with eugenics.

Anonymous said...

Brian Palmer, just another anti-hbd Jewish obfuscator who's not Jewish.

Anonymous said...

Im sure Im not the only one to notice the irony that a Venn diagram of those who most vocally denounce eugenics would show a very large overlap with those who most strongly support abortion.

There are exceptions of course.

Anonymous said...

"Oh, they are more than willing to practice on others, too. Among ob/gyns, Jews, females and irreligious are most likely to perform abortions, while evangelicals and catholics are the least likely."

Meanwhile, the people most likely to have abortions are black and hispanic.

Just coincidence of course.

Svigor said...

I don't share any of your ideas on what conclusions to reach regarding the obvious differences between populations on all kinds of measures. I don't believe the term IQ is precise enough for one though it is the major focus around here. I'm also a little skeptical about that term "evolution" unless by it you mean change more than a supposed move up the ladder to, say, transhumanism.

Since no one knows who you are, and therefore, no one has any idea how good your judgement is, no one gives a shit about your assertions or unsupported opinions.

Anonymous said...

"I once asked Google if you have to be Jewish to write for Slate. I was surprised to only find two relevant responses."

Later, from another commenter:

"Slate writer yearns for Freud to return from the dead and bash the uppity goyim over the head with some good old-fashioned critique."

Is there any evidence to suggest that Brian Palmer is Jewish? His name doesn't even sound like a fake Jewish name.

David said...

>It’s still the case that identical twins are more genetically similar than other kinds of siblings.<

As this quote makes clear, the big obstacle the biological flat-earthers have is the very concept of "genetics."

So the thing they'll attack next is probably genes. "Genes are a racist fiction." "We don't even know what we mean by genes." "Genes were dreamed up by a crazy gentile monk (= pederast??) 100+ years ago, to explain peas. We are not peas, we are PEOPLE!" Etc. Watch for it.