February 25, 2003

Bill Dickens and James Flynn on Heredity, Environment, and IQ

Nathan Newman points me to an online version of Bill Dickens's and James Flynn's theory that attempts to explain all of the puzzling facts about heredity, environment, and measured test-score IQ. The theory is plausible. It is coherent. It is powerful and sensible. And it is politically correct as well:


Heritability Estimates vs. Large Environmental Effects: The IQ Paradox Resolved: How could solid evidence show both that environment was so feeble (kinship studies) and yet so potent (IQ gains over time)?

Dickens has proposed a model that we believe solves the paradox. It assumes that people who have an advantage for a particular trait will become matched with superior environments for that trait; and that genes can derive a great advantage from this because genetic differences are persistent. A genetic advantage remains with you throughout life, while environmental differences tend to come and go, unless sustained by the steady pressure of genes.

Take those born with genes that make them a bit taller and quicker than average. When they start school, they are likely to be a bit better at basketball. The advantage may be modest but then reciprocal causation between the talent advantage and environment kicks in. Because you are better at basketball, you are likely to enjoy it more and play it more than someone who is bit slow or short or overweight. That makes you better still. Your genetic advantage is upgrading your environment, the amount of time you play and practice, and your enhanced environment in turn upgrades your skill. You are more likely to be picked for your school team and to get professional coaching.

Thanks to genes capitalizing on the powerful multiplying effects of the feedback between talent and environment, a modest genetic advantage has turned into a huge performance advantage. Just as small genetic differences match people with very different environments, so identical genes tend to produce very similar environments?even when children are raised in separate homes.

In other words, kinship studies of basketball, no matter whether they involved people with identical genes or different genes, would underestimate the potency of environmental factors. Playing, practicing, being on a team, coaching, all of these would be credited to genes?simply because differences in them tend to accompany genetic differences between individuals. Genes might seem to account for as much as 75 percent of variance across individuals in basketball performance. If someone showed that the present generation was far more skilled at basketball than the last (as indeed they are), Jensen's math would prove that it was impossible. It would show that those aspects of environment that are not correlated with genes (which is all that environment gets credit for in kinship studies) were very feeble. So feeble that the present generation would have to be within the top one percent of the last in terms of quality of environment for basketball.

The cognitive ability differences measured by IQ tests may have the same dynamics. People whose genes send them into life with a small advantage for these abilities start with a modest performance advantage. Then genes begin to drive the powerful engine of reciprocal causation between ability and environment. You begin by being a bit better at school and are encouraged by this, while others who are a bit 'slow' get discouraged. You study more, which upgrades your cognitive performance, earn praise for your grades, start haunting the library, get into a top stream. Another child finds that sport is his or her strong suit, does the minimum, does not read for pleasure, and gets into a lower stream. Both of you may go to the same school but the environments you make for yourselves within that school will be radically different. The modest initial cognitive advantage conferred by genes becomes enormously multiplied.

Once again, just as different genes are matched with very different environments, so identical genes will be matched with very similar environments. You and your separated identical twin will get very similar scores on IQ tests at adulthood. Using Jensen's model, genes will get credit for all of the potent environmental influences you both share. And environment will appear so feeble that it could not possibly account for the huge IQ advantage your children enjoy over yourself. Our model shows why this is a mistake. It shows that kinship studies hide or 'mask' the potency of environmental influences on IQ. Therefore, they do not really demonstrate the impossibility of an environmental explanation of massive gains over time.

The model's next task it to suggest just how environment performs its demanding role. Social forces affecting the whole of society can provide something that an individual's life experiences normally do not. They provide environmental influences that are just as persistent over time as the individual's genetic endowment, and that are not at the mercy of genes. After all, the present generation has no advantage in genetic quality over the last, indeed, it is often argued that the reverse is true due to the lower fertility of the more highly educated. So between generations, the mask slips and environmental forces stand out in bold relief. Relatively small environmental differences between generations gain enormous potency just as small genetic differences between individuals did: They seize control of the powerful reciprocal causation that exists between cognitive ability and environment.

No one knows for certain what environmental trends caused massive IQ gains but we can suggest a scenario consistent with their history. There is indirect evidence that massive gains in the cognitive abilities IQ tests measure began in Britain as far back as those born in 1872. They probably began with the industrial revolution and were there waiting for IQ tests to be invented to measure them. The industrial revolution upgraded years and quality of schooling, nutrition, disease control, all things that could have had a profound influence in raising IQ, at least up to about 1950.

After 1950, in nations like the US and Britain, IQ gains show a new and peculiar pattern. The are missing or small on the kind of IQ tests closest to school-taught material like reading and arithmetic. They are huge on tests that emphasize on-the-spot problem-solving, like seeing what verbal abstractions have in common, or finding the missing piece of a Matrices pattern, or making a pattern out of blocks, or arranging pictures to tell a story...

Take it away, Mr. Drum...

Posted by DeLong at February 25, 2003 03:30 PM | TrackBack

Comments

It seems that Dickens & Flynn have finally explained E.O. Wilson's theories of inheritance and inateness without the call of ethnicity. I would like to see this applied to educational expectations rather than standardized testing.

Posted by: PT Martin on February 25, 2003 03:49 PM

Tangentially, but hopefully not so much that this comment gets axed, how would his solution explain this?

BOY BEATS KASPAROV
http://www.sky.com/skynews/article/0,,30200-12255666,00.html

The boy, from Baku, Azerbaijan, has already run Kasparov - world champion from 1985-2000 - close in speed chess.
...
Kasparov, who is also from the ex-Soviet republic of Azerbaijan, has climbed back to the top of the world ratings.

Was there some point in history when those talented in chess were relocated to Azerbaijan to hone their skill?

Posted by: Brian on February 25, 2003 03:50 PM

"A genetic advantage remains with you throughout life, while environmental differences tend to come and go, unless sustained by the steady pressure of genes. "

Hmm.

Pre-natal/early childhood nutrition, quality of intellectual stimulation in the first few years of life, parental attitudes towards reading/inellectual pursuits, parental displayed skills of networking and interpersonal problem-solving, parental attitudes towards leisure time, parental attitudes displayed concerning the use/abuse of drugs and alcohol, readily available kinship (and local social) networks, the skills learned in using them/watching them used, beliefs about how one will be treated by strangers, the prerception of the utility of long-term planning, ....


And this is in a restricted context (such as modern first-world environment).

Do these people really accept the simple fact that an organism's environment can have lasting effects on it?

Posted by: Barry on February 25, 2003 04:02 PM

With reference to Brian's comment, I note the following observation on Usenet:

"In a country where the game has nearly 100% saturation through the population, one might expect some masters to emerge even if the primary training tool of the Soviet School had been the practice of breaking coconuts with one's forehead."

-- Kevin Croxen, rec.chess.games.politics, April 25, 2002

This bears on Prof. DeLong's post, somehow.

(Full disclosure: I am not Kevin Croxen.)

Posted by: alkali on February 25, 2003 05:37 PM

No question but that nutrition and health care ought to have a strong influence on IQ. This would explain the steady rise in IQ since 1872 in London.

Explaining the peculiar pattern in IQ improvement since about 1950 is more difficult . . . . although most experts and amateurs accept the steady increase in IQ over the past 100 years or so, I'm not sure that the peculiar improvement in spacial abstractions is as accepted a phenomena (yet).

Posted by: Anarchus on February 25, 2003 05:54 PM

The Dickens & Flynn paper summarizes the evidence that the effects of short-term interventions eventually fade out: Head Start and other preschool programs, even adoption. The only lasting way to raise IQ (short of altering genes) is to change the social environment, i.e. culture and society. So, what is necessary to raise African-American IQ? A change in their culture (to more resemble that of whites)? That doesn't sound very politically-correct, but maybe PC standards are changing.

You might also be interested in Flynn's response to one of its critics on the paper here:

http://taxa.psyc.missouri.edu/bgnews/2001/msg00174.html

Posted by: tc on February 25, 2003 06:26 PM

Dickens' theory sounds reasonable to me.

I'm beginning to wonder if either (a) nobody actually read my original post in the first place or (b) I'm a much worse writer than I thought. My original post argued exactly this: the available evidence indicates that traits like intelligence have some basis in the genes, but they also have substantial basis in environmental factors, and these environmental factors are more than enough to account for observed group differences. In other words, you don't have to discard the notion that IQ is partially heritable in order to believe that group differences are *not* based on genes. This is exactly what Dickens is arguing, so why would I disagree with him?

I quite agree that the Flynn effect is one piece of evidence in favor of this, and Dickens' model suggests a plausible reason for it.

However, I also believe that "intelligence" is a reasonable field of study and a useful concept, one that will become even more important as time goes by. This seems to be what got me into so much trouble.

Posted by: Kevin Drum on February 25, 2003 08:05 PM

This whole line of thinking is (at least sometimes) called "interactionism" and was once the domain of a significant movement in development studies. It goes back to folks like Vygotsky were working in the pre-genetic era and saw learning as a path-dependent process in which the ability to acquire a new skill was dependent on the skills already acquired and the cultural millieu in which those skills were exercised.

Applying the same thinking to heredity is something that is starting to take off. The expression of genes is controlled to some degree by an environment which is - in turn - controlled to some degree by gene expression. It creates this feedback cycle that makes it hard to link actual outcomes with specific genes because cause doesn't go girectly from genes to outcomes. Results are always conditioned on unseen and unknown environmental conditions which may not be constant.

Posted by: Scott Martens on February 25, 2003 10:11 PM

This whole line of thinking is (at least sometimes) called "interactionism" and was once the domain of a significant movement in development studies. It goes back to folks like Vygotsky were working in the pre-genetic era and saw learning as a path-dependent process in which the ability to acquire a new skill was dependent on the skills already acquired and the cultural millieu in which those skills were exercised.

Applying the same thinking to heredity is something that is starting to take off. The expression of genes is controlled to some degree by an environment which is - in turn - controlled to some degree by gene expression. It creates this feedback cycle that makes it hard to link actual outcomes with specific genes because cause doesn't go girectly from genes to outcomes. Results are always conditioned on unseen and unknown environmental conditions which may not be constant.

Posted by: Scott Martens on February 25, 2003 10:12 PM

It seems somehow a sort of supernatural exceptionalism to believe that intelligence is not substantially mediated by genetics. What struck me as evil? about The Bell Curve was the lack of concern and proposals for social policy regarding those in the lower sections of IQ. It has long seemed to me that the less intelligent suffer from two directions. Liberals who believe that IQ does not exist, and Conservatives who think that its their 'fault' for not doing better, a sort of social darwinism. My own view is that it is a sick society which does not figure out how to use and value the talents and aspirations of the majority of its members, including those who are not so bright.

Posted by: secular clergyman on February 25, 2003 11:37 PM

RE: Scott's post.

Studies in the field of psychiatry consistently show that an identical twin -where the twins have been separated at birth- have about a 50% chance of developing a serious mental illness, like schizophrenia, if the sibling has the illness.

Modern psychiatric thought attributes serious mental illness to genetic factors, but obviously environment (nurture) must play an equal role; determining somehow whether or not the genetic predisposition will be activated.

Attempts to identify what environmental factors are influencial in activating the inherited tendency have not yet been fruitful, (ie) the "schizophrenogenic family" concept has been discarded and several multivariant analyses of environmental conditions have not found any strong correlations.

Posted by: E. Avedisian on February 26, 2003 12:29 AM

Interventions are a small part of a child's environment (compared to parents and neighborhood). IMO, the name comes from the fact that the goal is to make a change on existing background variables which are believed to have strong influence.

Posted by: Barry on February 26, 2003 01:44 AM

I like this idea a lot, not least because it puts a lot of the environmental weight on learning by doing and network effects. Which provokes the thought, what spectacular new IQ leaps might we expect from those in the 'net generation'? And what will be the consequences for the relative labour market value of the older generations, and what are the consequences of this type of theory for those countries where the balance is tilted towards the young, and those where the balance is tilted towards the old. More from the people who brought you Darwin's Dangerous Idea (See, in particular, the Descent of Man). Needs a lot more fleshing out, but, as I said, it sounds good.

Posted by: Edward Hugh on February 26, 2003 02:02 AM

"Attempts to identify what environmental factors are influencial in activating the inherited tendency have not yet been fruitful, (ie) the "schizophrenogenic family" concept has been discarded and several multivariant analyses of environmental conditions have not found any strong correlations."

Alas, the search for genetic sources of schizophrenia has exactly the same problem, which is the entire point. People have this equation in their head, genes + environment = outcome, which is exactly what this article is trying to undermine. What can all too easily happen is that a gene causes something, which causes something else, which under some environmental condition which may be caused by some outside factor or even some other gene, causes something else. The inability to identify strongly causative environmental factors mirrors precisely the failure to find strongly causative genetic factors (e.g. actual genes) for virtually everthing that does not have a known biochemical cause, and using twin adoption studies in lieu of actual genetics is inadequate for exactly the reasons Flynn et al outline.

Look at Flynn's discussion of basketball. Some gene X is not directly causative of outcome Y, but - for entirely cultural reasons - it places the person in a position where the environmental causes of Y are more likely to act on them. Twin adoption studies are completely unable to measure the differences or commonality of the twins' environments because there is no general metric for doing so. Adoptees tend to end up in middle class or better families, generally in the same country and often the same general area, usually in the same ethnic group and the same or similar religion. A common culture is very likely to act on the same genes in both cases. Exactly which components of the culture are linked causally to whatever we're studying may be as hard to find as the genes.

I know that the schizophrenic family theory is discredited, as well it should be and as I know well since it's an awfully common condition in my family. (In fact, at one time in my life I read a lot of studies linking schizophrenic family origins to higher IQ.) But the support for genetic theories of schizophrenia are as weak as the old environmental theories because they rely on exactly the same fallacy: deducing cause directly from correlation. That schizophrenic families produce schizophrenic children does not prove that schizophrenia is a consequence of family environment, nor does genetic correlation in twin adoption studies prove that it is genetic in origin.

Consider this example: if we found a gene that correlated well to heart disease, we would say that heart disease has some genetic component. But what if the gene in fact had nothing to do with heart disease but instead was linked to nicotine addiction? People who have this gene but never touch a cigarette have rates of heart disease identical to other non-smokers.

Is heart disease then caused by genes, or is it caused by smoking? If we were unaware of the health consequences of smoking, what would we conclude? If we lived in a society where nearly everone smoked, but in varying amounts, would it ever occur to anyone to look at smoking as a possible cause if a genetic correlation had already been established?

It is exactly this class of argument which needs to be brought to bear on all claims of heritability which do not include a specific pathology, e.g. gene X causes protein Y which causes condition Z. Where the latter exists, we can independently verify the pathology and the heritablity studies only serve to reinforce the claim. Where it does not exist we must respond with great skepticism.

Posted by: Scott Martens on February 26, 2003 02:07 AM

Hmmmm ... what would happen if you, genetically, had a skin pigmentation disorder which made people in the education industry instinctively shy away from you, regard you as a troublemaker and fail to pay you attention? What would be the feedback effects then? Given that "being black" is exactly such a genetically inherited condition of pigmentation.

Posted by: dsquared on February 26, 2003 06:02 AM

Scott Martens makes a lot of sense to me (tip of the hat).

Just to muddy the waters further with a thought experiment: what if you took identical twins and ran them through the identical environment several hundred times? Would you expect and get identical results (incidence of Schizophrenia, heart disease, basketball stardom, whatever), or would there be variation that would not be attributable to either genetics (as currently understood) or environment?

PS: I'm in the camp that our knowledge of heredity is not-yet-complete - so that there may be genetic differences between "identical" twins that we haven't uncovered yet. For example, the sheep Dolly was supposedly a genetic "clone" of her predecessor, but her telomeres were much shorter, and there may have been other genetic differences that modern bioscience hasn't even discovered yet.

Posted by: Anarchus on February 26, 2003 06:50 AM

The Dickens model does what good models sometimes do -- it makes clear what you sort of already knew. Sure, benefit follows on benefit, but that's not a very clear way of putting it. "Reciprocal causation" captures the idea well, makes things clearer. So hurray for the model and the modeler, no matter how the model holds up in the end.

Posted by: K Harris on February 26, 2003 09:00 AM

Yes, Scott, I agree with all of the points in your last post.

And thinking along those lines often ultimately leaves me in a very philosophical - if not spiritual - frame of mind.

Life is so replete with senendipity; so capricious. Even a single act - a single exposure to a stimulus - can deflect the development of genetic potential in an individual onto a path for better or for worse.

I am compelled to remind myself to try to always put forth the maximum ammount of positive influence when interacting with others; especially the young.

Posted by: E. Avedisian on February 26, 2003 11:44 AM

I'm sure I'm not understanding as well as I thought I was.

The article asserts that the model explains why black adoptees in cross racial adoptions do not gain IQ points.

How does the model explain this phenomenon? I got the other points, but this one alludes me.

Posted by: E. Avedisian on February 26, 2003 12:15 PM

Sorry if I've been ranting lately. The whole IQ and heredity thing runs over several boards, making the arguments blurr sometimes. Especially for me, since I am a linguist who holds the publicly unpopular position that language is not innate in the sense meant by Chomsky, Pinker and others.

E. Avedisian, Flynn's model could - as D^2 points out - mean that just by virtue of having black skin, even when one is adopted and raised in an otherwise white home, educational opportunities might not be open to you. Teachers and other students might respond differently.

There is a fairly strong school of thought in development theory that places a lot of stock in peer groups as the major predictor of social outcomes. Judith Harris was the first to really push this theory into the mainstream, but it has deeper roots. A black kid - regardless of the kind of home he lives in - is probably likely to join a predominantely black peer group. This peer group is likely to be the group with the least regard for school or "white" culture. This might be the cause of the lower standardised test scores for blacks even when adopted into white households.

Posted by: Scott Martens on February 26, 2003 12:36 PM

>>Then genes begin to drive the powerful engine of reciprocal causation between ability and environment. You begin by being a bit better at school and are encouraged by this, while others who are a bit 'slow' get discouraged. <<

Substitute "black" for "slow" above and you have your answer. Paul Condon coined the useful phrase "institutional racism" for the tendency of people who are not racists themselves to make systematically biased assumptions and judgements which have severely racist effects, and it's just as common in the education profession as it is in the police force.

Posted by: dsquared on February 26, 2003 12:40 PM

Anarchus, there are a pair of cloned cats with different spots, but everyone who breeds cats knows that a cat's markings are hereditary. You can read the article at http://www.msnbc.com/news/862384.asp

We know that proteins other than DNA and RNA can carry hereditary information. Back in the 50's, this was a hypothesis that was considered as an alternative to Crick's DNA theory. Crick was vindicated and the alternatives dissappeared. With the arrival of prions in the public consciousness (thanks to all those mad cows) the possiblity that environmental proteins could carry inheritable information that affects larger organisms (e.g., us humans) is something that no longer appears ridiculous.

Of course, that doesn't mean it's true. No one has ever established clearly that something like that is going on in even single celled organisms as far as I know, although genes aren't much good outside of a cellular environment able to interpret them. The cellular environment is mostly a matter of particular proteins and the catalytic reactions they engender.

Posted by: Scott Martens on February 26, 2003 01:19 PM

"However, I also believe that 'intelligence' is a reasonable field of study and a useful concept, one that will become even more important as time goes by."

Intelligence is not a useful concept, and will become even less important as time goes by.

Intelligence is currently not a useful concept because: a) IQ appears to be increasing by 9-20 points per generation, b) there are 9-20 points difference among the "races," and c) approximately 15 point standard deviation, overall.

In other words, there simply isn't enough difference to "write home about."

Further, "intelligence" has virtually no effect on the performance of societies, as is demonstrated by North Korea vs South Korea, East Germany vs West Germany, Taiwan vs the "People's Republic" of China (especially before 1980), Haiti vs the Dominican Republic, etc.

Finally, intelligence will become *less* important, not more important. Human IQs are increasing by 9-20 points per generation (20 years). In the next 20 years, computers will go from the current level of intelligence of a lizard (i.e., near zero) to smarter than any human being (i.e., well over 160). Further, in the 20 years following that, computer intelligence will be so far off the IQ scale, that a single computer will have the combined intelligence of a million human minds. In other words, in the next 2 generations, the human mind will essentially be obsolete. The least intelligent human will be able to buy computing power that will allow him or her to exceed the intelligence of any present human.

Human intelligence is a red herring, that distracts from far more important subjects.

Posted by: Mark Bahner on February 26, 2003 03:22 PM

Dickens's and Flynn's theory offers opportunities to explore a secondary hypothesis that could provide a better understanding of the impact of racism (and sexism) on the individual. Perhaps racism is an enviromental field that, regardless of the genetic predisposition of the individual, distorts and reshapes the genes search for positive feedback by filling the environment with specific targeted disincentives. Such that an African-American with above average IQ would encounter significant external resistance to their natural inquisitiveness, even today. Because it is likely that others in their family have met in their pasts with the same defeats and obstacles, perhaps in more degrading forms, there may exist a presumption of hardship that would create a culture that seeks other modes of expression or attempts to redirect the individual towards safe modes of actualization. The flip side of this would be to analyze the privileged environmental field that white Americans have generally existed within. The question is whether or not our society necessarily condemns us to a zero sum game when it comes to the persistent fiction of race.

Langston Hughes poem, "Harlem: A Dream Deferred", reminds me that our poets frequently seem to know before our scientists:

What happens to a dream deferred?

Does it dry up
like a raisin in the sun
Or fester like a soreó

And then run?
Does it stink like rotten meat?
Or crust and sugar overó

Like a syrupy sweet?

Maybe it just sags
like a heavy load.

Or does it explode?

PBS is exploring this same notion by revisiting a homespun experiment in the color divide:

http://www.pbs.org/wgbh/pages/frontline/shows/divided/

Posted by: Ernesto Villagro on February 27, 2003 11:39 AM

I tend to find merit in the feedback loop hypothesized between genetics and environment.
Do to boredom and being a goof-off in early elementary school, I ended up a year or 2 behind in reading and math up through 3rd grade, when my mother insisted I wasn't slow, but above average, and had me tested for our school districts gifted student program.

I tested extremely high, and was soon much more engaged with learning, as my teachers now thought that I was bright, and treated me as such.

Within 2 years I went from being behind my class to reading at college level.

Would I have fallen in love with learning and books, had I been treated as I had formerly?

Probably not, and with my large physical size, could easily have ended up an athlete, had I had coaching in sports instead of academics.

Posted by: David Mercer on February 28, 2003 02:32 AM

One can go back a bit further than Vygotsky for a statement of "interactionism". It comes from a decidedly non-Marxist amateur bricklayer (also known for other things) named Winston Churchill:

"We shape our buildings
and afterwards
our buildings shape us."

More deeply, some simple numbers should make it evident that detailed architectural plans are not to be found in the genome. While there is more to a living being than the nuclear genome - in particular the wonderful mystery of a living single cell (which must exist "BEFORE" the genome can be expressed!) - most will allow that what makes people (or other complicated critters like cats) special compared to single-celled creatures is contained within the genome. (And note we share about 98% of that genome with chimps, at that!)

http://www.edge.org/q2002/q_marcus.html says:
"The DNA does not... provide a literal blueprint of a newborn's mind. We have only around 35,000 genes, but tens of billions of neurons. How does a relatively small set of genes combine to build a complex brain? As Richard Dawkins has put it, the DNA is more like a recipe than a blueprint. The genome doesn't provide a picture of a finished product, instead it provides a set of instructions for assembling an embryo..."

http://www.kurzweilai.net/articles/art0288.html
elaborates this way:
"The human genome is 800 million bytes, but if we eliminate the redundancies... we are left with only about 23 million bytes... The limited amount of information in the genome specifies stochastic wiring processes that enable the brain to be millions of times more complex than the genome which specifies it. The brain then uses self-organizing paradigms so that the greater complexity represented by the brain ends up representing meaningful information."

Part of that self-organization involves sampling the post-natal environment, even for functions you might think are very primal and invariant. For example, the visual system of mature cat brains depends on their visual experiences when in a critical neonatal plastic brain state. If raised in an artificial environment without any vertical edges, no neurological vertical edge detectors will be developed & the mature cat will be irreversibly blind to such visual features.

So while the genome controls whether we develop into humans or cats, and controls a lot about what, say, a human will be like, it really tends to provide contingency programs, rather than predestined structural details.

So I am not surprised that something like the Flynn Effect can be observed, because it is not obvious that a particular fixed (e.g. "maximized") IQ will have optimal survival value in each and every potential human enviroment. IQ elasticity within a SINGLE individual can possibly make that individual's survival and reproduction more robust.

As Darwin pointed out long ago, Nature does not always see fit to run the actual survival experiment - in addition to Natural Selection (NS) there is Sexual Selection, which we might think of as a sort of cybernetic simulation which effects computational accceleration of NS.

The ability to vary IQ, height, et cetera (within limits) within an individual according to a program whose structure is strictly determined by genetics - but whose operation samples the environment to set design parameters - would perform a service similar to that of Sexual Selection - optimization of survival without resort to an additional Natural Selection experiment.

Of course, the fact that IQ "manifestation" operates through a synergistic interaction with the environment, e.g. active selection of an environment which serves to enhance or depress eventual IQ relative to what it would be in the absence of such selection - does not seem to be to invalidate the notion that IQ is essentially "determined" by genetics - just in a more round-about way than might be naively apprehended.

I would not be surprised if one desire of the Dickens-Flynn paper authors is to encourage the ambition that IQ might be "programmed" by non-genetic social means if the interlopers are stubborn and brutal enough.

But if you want horses to be race-horses, and you can get that by breeding horses that like to run, and so build up muscles that make running more fun and effective at once, et cetera in a feedback loop, why bother some poor horse that would just rather be left alone to graze? Just breed the horses that naturally want to do what you will them to do - and to be, and spare other horses who would rather do otherwise the whip. Why not just start with the right design in the first place?

Posted by: Ron Feigenblatt on July 17, 2003 07:55 AM
Post a comment