January 10, 2009

Steven Pinker gets his genome tested ...

... and discovers he has the Bald Gene.

In a long article in the New York Times Magazine, "My Genome, My Self," the author of The Blank Slate recounts all that he has learned about himself from having his genome sampled, which turns out to be unsurprisingly modest.

The most prominent finding of behavioral genetics has been summarized by the psychologist Eric Turkheimer: “The nature-nurture debate is over. . . . All human behavioral traits are heritable.” By this he meant that a substantial fraction of the variation among individuals within a culture can be linked to variation in their genes. Whether you measure intelligence or personality, religiosity or political orientation, television watching or cigarette smoking, the outcome is the same. Identical twins (who share all their genes) are more similar than fraternal twins (who share half their genes that vary among people). Biological siblings (who share half those genes too) are more similar than adopted siblings (who share no more genes than do strangers). And identical twins separated at birth and raised in different adoptive homes (who share their genes but not their environments) are uncannily similar.

Behavioral geneticists like Turkheimer are quick to add that many of the differences among people cannot be attributed to their genes.

Identical twins raised apart tend to be almost as similar as identical twins raised together, although part of the reason is that identical twins raised alone don't feel the need to distinguish themselves from their twin by developing something unique about themselves. Horace Grant, the skinny power forward on Michael Jordan's first three championship teams, would probably have become a quick forward if he hadn't grown up playing on youth teams alongside his identical twin Harvey Grant, who became an NBA All-Star shooting forward, while Horace was given the role of rebounding forward.

I know two pairs of adult identical twins, the Brimelows and the Woodhills, and the personal affects vary mildly among the Brimelows and moderately among the Woodhills.
But not all variation in nature arises from balancing selection. The other reason that genetic variation can persist is that rust never sleeps: new mutations creep into the genome faster than natural selection can weed them out. At any given moment, the population is laden with a portfolio of recent mutations, each of whose days are numbered. This Sisyphean struggle between selection and mutation is common with traits that depend on many genes, because there are so many things that can go wrong.

Penke, Denissen and Miller argue that a mutation-selection standoff is the explanation for why we differ in intelligence. Unlike personality, where it takes all kinds to make a world, with intelligence, smarter is simply better, so balancing selection is unlikely.

Is smarter simply better? If it takes, say, bigger brains, the answer isn't terribly clear. Analogously, Intel assumed that faster clockspeed computer CPU chips were simply better for about 15 years. But the struggle to break the 4.0 gigahertz barrier proved overwhelming and so Intel has given up and gone in different directions in recent years, when most chips sold seem to be between 2.0 and 3.0 gigahertz, although performance keeps improving.

Keep in mind that Intel has big advantages over natural selection in getting from one performance peak to another. For example, if Intel decides that its strategy of single chips with ever faster clockspeeds is heading toward a deadend, it can simultaneously start working on an R&D project for double core and quad-core chips with moderate clockspeeds. At first, the new type of CPUs won't be as good as the old type, but it doesn't have to sell the beta versions of the changed design. It can keep making them and throwing them away until the new style chips are as good as the competition's old style chips.

In contrast, natural selection doesn't provide you much of a laboratory in which to putter around while you're working the kinks out of your next model while your factory keeps churning out the satisfactory current model.

Similarly, bigger brains require more food. They make you more likely to tip over and hurt yourself. They require your mother to have a wider pelvis so she won't die in childbirth, which makes her a slower runner.

But intelligence depends on a large network of brain areas, and it thrives in a body that is properly nourished and free of diseases and defects. Many genes are engaged in keeping this system going, and so there are many genes that, when mutated, can make us a little bit stupider.

At the same time there aren’t many mutations that can make us a whole lot smarter. Mutations in general are far more likely to be harmful than helpful, and the large, helpful ones were low-hanging fruit that were picked long ago in our evolutionary history and entrenched in the species. One reason for this can be explained with an analogy inspired by the mathematician Ronald Fisher. A large twist of a focusing knob has some chance of bringing a microscope into better focus when it is far from the best setting. But as the barrel gets closer to the target, smaller and smaller tweaks are needed to bring any further improvement.

The Penke/Denissen/Miller theory, which attributes variation in personality and intelligence to different evolutionary processes, is consistent with what we have learned so far about the genes for those two kinds of traits. The search for I.Q. genes calls to mind the cartoon in which a scientist with a smoldering test tube asks a colleague, “What’s the opposite of Eureka?” Though we know that genes for intelligence must exist, each is likely to be small in effect, found in only a few people, or both. In a recent study of 6,000 children, the gene with the biggest effect accounted for less than one-quarter of an I.Q. point. The quest for genes that underlie major disorders of cognition, like autism and schizophrenia, has been almost as frustrating. Both conditions are highly heritable, yet no one has identified genes that cause either condition across a wide range of people. Perhaps this is what we should expect for a high-maintenance trait like human cognition, which is vulnerable to many mutations.

The hunt for personality genes, though not yet Nobel-worthy, has had better fortunes. Several associations have been found between personality traits and genes that govern the breakdown, recycling or detection of neurotransmitters (the molecules that seep from neuron to neuron) in the brain systems underlying mood and motivation....

But it seems even less plausible to say that more or less of any major psychological trait is "simply better." We may have our subjective preferences, but the major personality traits are likely to be ones on which normal variation doesn't much change average Darwinian fitness over the generations.

Even if personal genomics someday delivers a detailed printout of psychological traits, it will probably not change everything, or even most things. It will give us deeper insight about the biological causes of individuality, and it may narrow the guesswork in assessing individual cases. But the issues about self and society that it brings into focus have always been with us. We have always known that people are liable, to varying degrees, to antisocial temptations and weakness of the will. We have always known that people should be encouraged to develop the parts of themselves that they can (“a man’s reach should exceed his grasp”) but that it’s foolish to expect that anyone can accomplish anything (“a man has got to know his limitations”). And we know that holding people responsible for their behavior will make it more likely that they behave responsibly. “My genes made me do it” is no better an excuse than “We’re depraved on account of we’re deprived.”

Many of the dystopian fears raised by personal genomics are simply out of touch with the complex and probabilistic nature of genes. Forget about the hyperparents who want to implant math genes in their unborn children, the “Gattaca” corporations that scan people’s DNA to assign them to castes, the employers or suitors who hack into your genome to find out what kind of worker or spouse you’d make. Let them try; they’d be wasting their time.

The real-life examples are almost as futile. When the connection between the ACTN3 gene and muscle type was discovered, parents and coaches started swabbing the cheeks of children so they could steer the ones with the fast-twitch variant into sprinting and football. Carl Foster, one of the scientists who uncovered the association, had a better idea: “Just line them up with their classmates for a race and see which ones are the fastest.” Good advice. The test for a gene can identify one of the contributors to a trait. A measurement of the trait itself will identify all of them: the other genes (many or few, discovered or undiscovered, understood or not understood), the way they interact, the effects of the environment and the child’s unique history of developmental quirks.

Well said.

On the other hand, as futile as individual genomics is likely to prove to be relative to current expectations., the Law of Large Numbers suggests that racial genomics is likely to prove more fertile.

My published articles are archived at iSteve.com -- Steve Sailer

24 comments:

Justin Halter said...

"At the same time there aren’t many mutations that can make us a whole lot smarter. Mutations in general are far more likely to be harmful than helpful, and the large, helpful ones were low-hanging fruit that were picked long ago in our evolutionary history and entrenched in the species."

This is bizarre. So the initial jump to human-ness was a "low-hanging fruit" that produced profound gains. But since then, it's 99.9% harmful mutations?

A gene mutation is a gene mutation, it is nonsense to speak of some of them as "entrenched".

What he is saying is, humans appeared with a giant leap forward that basically defies everything we observe about mutations. But that is definitely not "miraculous", no sir, it is just "low-hanging fruit". God just adjusting his microscope, ahem, er, uh, I mean, Chance just adjusting its microscope.

Anonymous said...

"Forget about the hyperparents who want to implant math genes in their unborn children, the “Gattaca” corporations that scan people’s DNA to assign them to castes, the employers or suitors who hack into your genome to find out what kind of worker or spouse you’d make. Let them try; they’d be wasting their time."

True genetic engineering of embryos may be out of reach for a while.

But screening multiple embryos for intelligence and looks is going to be available as IVF and preimplantation genetic diagnosis are perfected.

Mark Seecof said...

Steve, I recall you wrote about an interview with Flynn in which, among other things, he was quoted (perhaps misquoted) saying that IQ could hardly get any higher. I thought that was nonsense and the notion you quoted today that for some unexplained reason, mutations with a large positive effect on IQ are nearly impossible is also nonsense.

Nobody has any basis for such an assertion.

Now, the question of whether an IQ-related mutation would increase a carrier's (inclusive) fitness enough to spread is a different can of worms.

I feel pretty confident suggesting that a new mutant gene boosting IQ a large amount might not spread very quickly, depending on the population in which it appeared. We know that in our (USA) society smarter people produce fewer offspring than median-IQ people, and I suspect that very smart people living among fairly dull people reproduce at a very low rate.

A mutation which produced high IQ might only be able to spread in a population which already had pretty high mean IQ. A genius mutant in a low-IQ society might not be able to find a mate.

Actually, this problem suggests another reason to limit low-IQ immigration to high-IQ countries. As immigrants reduce the mean IQ in some country, they likely reduce the speed with which any higher-IQ mutation could spread through its population.

Indeed, there may be a positive feedback loop which operates on some populations (e.g., Ashkenazim). In a high-IQ population, an high-IQ mutant won't be too weird to mate, so the mutation in question can spread. Even if the same mutation appears in an individual in a low-IQ population, the carrier may have trouble reproducing and the mutation will go extinct. Since IQ-boosting mutations can survive more easily in higher-IQ groups, those groups will tend to grow their IQ leads over time. If the high-IQ group becomes less reproductively isolated (e.g., USA Ashkenazim) it may cease to gain IQ at the previous high rate.

Anonymous said...

The obsession with finding "gene for <insert your favorite trait here>" just doesn't seem to go away. For some reason, the "reductionist" approach (in the wrong sense of the word) seems to be getting in the way.

Think of it like cars: no car model of any manufacturer has a driving wheel that is totally different from that of the others; same for the dashboard, the windshield, the 4 wheels, the transmission, etc. It's the unique combination of the variations in each and every one of these that makes say a Ford or an Austin Martin what it is -- assuming a car brand/model can be verifiably shown to be unique.

It's most probably the same thing for "race," but that requires a more "holistic" (is this spelling correct? Shouldn't it be "whol-istic?") approach to evaluating the "gene complexes" -- or perhaps "constellations."


JD

Jun said...

... and discovers he has the Bald Gene.

I always thought that was a wig! ;-)

Anonymous said...

Which cultural groups are still set up today in such a way as to arrange for the highest IQ people to have lots of children and the lower IQ people to have few or no children?

You see some high IQ couples with $20 million or more in Manhattan having five kids these days, but this is a very small impact.

What are the statistics in Japan and South Korea for example? Are the men with high IQ having more kids or fewer kids than their low iq countrymen? What about women?

Another interesting point - the young males that read this blog are of course aware that if they choose to marry a good looking low iq woman from a good looking low iq family, they can expect their children and grandchildren to be failures in life.

On the other hand, if they choose to marry an "average" looking woman with very high IQ from an average looking very high IQ family that they can expect their children and grandchildren to be successful in life.

The young men who read this blog I believe act accordingly.

However, what percentage of young men in America are taught this lesson? How many think about the IQ of their children and grandchildren before buying a ring?

And how about in Northern Europe - how about in East Asia - how aware are the young men in those countries that the IQ of their wife will in large part determine their legacy?

SFG said...

However, what percentage of young men in America are taught this lesson? How many think about the IQ of their children and grandchildren before buying a ring?

Why do you think the Ivy League elite insists on marrying each other? Why do you see so many nerdy white guys running around with Asian chicks? Look at the (probably more important) social skills: why do most women refuse to take up with nerds?

I don't know how many people can tell you the heritability of IQ, but the saying 'the apple doesn't fall far from the tree' has been well known for years. As Pinker says, common sense has integrated most of the useful knowledge here already.

Anonymous said...

SFG -

First of all, I am asking about males and femals who marry members of the same race and same religion. If we talk about cross religious or cross race mating, this discussion will go in the same direction that hundreds of other discussions on this blog have gone. I am trying to plow new ground here by talking exclusively about which cultures teach their young men and women to mate based on IQ

I think it is pretty clear that ashkenazi jews are taught from an early age to take in to consideration the IQ of their potential spouse.

I think it is also clear that upper caste South Asian Indians are taught the same thing.

But what about other groups - in what other cultures are young people encouraged to select a mate based on IQ, taught that IQ is more important than income, wealth, looks, or athletic ability ?

It is important to understand which cultures do this.

For example, there seem to be plenty of ultra high IQ mormons that have eight or nine children. Do they encourage these children specifically to marry other ultra high IQ mormons or is that not the pattern?

Statsquatch said...

I do not think that the reason to look for intelligence genes is to create a race of supersmarties. Genes code for proteins, proteins do things, and if we know what those things were we could do cool stuff. For example, if someone figures out what the fragile X gene does we might be able to make a drug that would create temporary retardation. That would be cool.

Mark Seecof said...

Oh, yeah. That microscope- focussing- knob analogy is clearly misapplied.

Changing, say, the shape of our microscope objective lens slightly might improve the image much more than tweaking its position.

Genetic mutations can change a biological system along many dimensions, not just one. It is totally wrong to think of mutations as necessarily moving a phenotype away from some magically pre-selected optimum.

We have an existence proof that higher- than- current- median IQ's are possible, which means a shift to a new higher median is also possible, assuming higher IQ doesn't produce lower fitness (under whatever population/ environmental conditions you care to suppose).

ben g said...

the major personality traits are likely to be ones on which normal variation doesn't much change average Darwinian fitness over the generations.

don't be so sure of that.. certain personality traits are associated with attracting women and having less inhibitions (extroversion).

see my post here at GNXP.

ben tillman said...

What he is saying is, humans appeared with a giant leap forward that basically defies everything we observe about mutations.

It's Gould's theory of punctuated equilibrium. Or Kubrick's "2001: A Space Odyssey". Which is to say, it doesn't sound too scientifically rigorous.

Danindc said...

I didn't understand most of that post but I don't think Harvey was an all star? I don't know, maybe it was a down year- he was always a disappointment to Bullet fans

Anonymous said...

I'm speaking from a relatively uninformed position, but I believe intel's focus on clockspeed was more about marketing than it was in a belief in its benefits. AMD's success marketing slower (in clockspeed) but faster (in performance) processors made them abandon the strategy. Intel seemed to think consumers were too stupid to figure out a "faster" (in clock speed) processor was actually slower (in performance), so they for some time peddled mediocre chips at higher clockspeeds than its competitor AMD. For some time now, Intel has produced better chips but only after abandoning the focus on clockspeed.

Ivy League Bastard said...

Punctuated equilibrium is not contradictory, it's almost a tautology that it has to occur. You can see it in all sorts of non-biological evolution, as well.

That is, a system will move around near some equilibrium until something (environmental or not) pushes it far enough away that it moves either in an avalanche (toward a qualitatively different regime, as in mass extinctions) or relatively rapidly toward the next stable equilibrium where it gets stuck until the next time. I think that what Gould & Co didn't emphasize, if they even were aware of it, is that these jumps should also occur at a variety of scales, in some fractal-like distribution.

There is an empirical issue for paleontologists as to how common or relevant Punctuated Equilibria, meaning the jumps big enough to see in the fossil record, are in animal evolution. There's no reason to assume they are a large, medium or small effect without looking at the data. But it's certainly not a matter of anything being "contradictory" or even counterintuitive.

Ivy League Bastard said...

dear anonymous,

assortative mating by IQ is no longer driven by religion, it is driven by the ubiquitous IQ-sensitivity (and IQ visibility) of outcomes in modern life.

If anything, religious mating would probably reduce the importance of IQ, because IQ compatibility becomes less important given the enormously greater compatibility implied by a common minority religion such as Jew, Mormon or Hindu. Also, religious teachings and church matchmakers tend to rank mates based on qualities that are unrelated to IQ or even negatively correlated with it (kindness, faith, loyalty, poverty, or just being single). Religious leaders would often take community interests into account and not just individual happiness when "setting up" their flock with each other, and that probably means more randomness in the mating outcomes.

I know smart people who used to date extremely-high-IQ people from outside their culture but eventually switched to merely high-IQs from the same culture. It was a good tradeoff; there was less of a need for superduper intelligence given the added cultural/religious commonality.

anony-mouse said...

Pinker has had 2 wives but no children.

How could there be a gene for voluntary (I'm assuming) childlessness?

airtommy said...

I didn't understand most of that post but I don't think Harvey was an all star? I don't know, maybe it was a down year- he was always a disappointment to Bullet fans

Harvey was never even close to making the All-Star team. Horace made it once.

Reg C├Žsar said...

Unlike personality, where it takes all kinds to make a world, with intelligence, smarter is simply better, so balancing selection is unlikely. --Pinker

Is smarter simply better? ...it seems even less plausible to say that more or less of any major psychological trait is "simply better." --Sailer

Even if high intelligence is better in the individual, it doesn't follow that it's better for the whole race. Indeed, the ability-- hell, the tendency-- of high IQs to override common sense might set an upper limit to a desirable median or mean IQ.

Look at the history of some of the most prominent smart and (in the past) fecund populations. China: the Taiping, Nien and Boxer rebellions, followed by Maoism. Ashkenazi Jewry: Freudianism and Marxism. New England Puritans: economic success, but a marked tendency to splinter sectarianism and secular causes-- and eventually swamped by their capitalists' immigrant guests.

Not a stellar record for the champions of intelligence. Nor is a visit to any major university town likely to reassure.

I'd submit that the "sweet spot", or "golden mean", of national intelligence might be closer to 105 than to 115. (Or, God help us, than to 130. Ever been to a Mensa First Friday?)

DYork said...

Genetic Code for Monogamy. From Hugh Hefner to Dagwood Bumstead with one gene.

DYork said...

anony-mouse said...Pinker has had 2 wives but no children.

From wiki:

...Pinker married Nancy Etcoff in 1980 and they divorced 1992; he married Ilavenil Subbiah in 1995 and they too divorced. His current wife is the novelist and philosopher Rebecca Goldstein. He has no children.

p earvolino said...

"Keep in mind that Intel has big advantages over natural selection in getting from one performance peak to another."

that's surprising. I mean, the difference between "teleologic" and "ateleologic" is only ONE LETTER.

Anonymous said...


Is smarter simply better? If it takes, say, bigger brains, the answer isn't terribly clear. Analogously, Intel assumed that faster clockspeed computer CPU chips were simply better for about 15 years.


This is a benighted view of how Intel is run. Even in introductory texts, such as Hennessy and Patterson's text on Computer Architecture, it is well known that clock speed or instructions per second (IPS) is only one of the considerations involved in overall performance. Among the others are: complexity of instruction set (RISC vs CISC), addressing modes, pipeline design, memory cache design, register allocation, and so on.

The reason why Intel (and all other semiconductor companies) keep boosting their clock speed is because once they have completed their microprocessor design (at a cost of nearly a billion dollars), they would like to recoup much of the cost and effort expended. Optimizing for yield (fewer defects on a wafer) and clock speed by improving their foundry process is the most straightforward way of doing so.

It is also a great marketing ploy. The great masses of consumers usually think that a 2Ghz processor is twice as powerful as a 1Ghz processor,

anony-mouse said...

Oops, I'm behind in my Pinkerology. But still no little Pinkers? If we're the product of our genes, how did this happen?