Environment is both feeble and overwhelmingly potent

Saturday, August 12th, 2017

Psychologists have been plagued by a paradox that suggests that environment is both feeble and overwhelmingly potent:

The paradox emerged from a debate about race. US whites outscore US blacks on IQ tests by 15 points. Does that gap have environmental causes or is it partially due to genes? In 1973, Arthur Jensen constructed a model that applied kinship data to group differences in IQ. Evidence from kinship studies showed identical twins separated at birth and raised in different homes grow up with very similar IQs. The fact that they have identical genes provides an obvious explanation. Jensen argued that fully 75 percent of IQ variance between individuals was due to genetic differences (a value which sits in the middle of the range recently endorsed by a select committee of the American Psychological Association for adult IQ). Jensen’s model showed that a purely environmental explanation of the black/white IQ gap meant that the environment of the average US black must be as unfavorable for the development of IQ as the lowest one percent of white environments measured in terms of their effects on IQ. That simply did not seem possible.

Jensen’s model seemed to preclude a purely environmental explanation for any large IQ gap between groups. Then, in 1987, Flynn showed that in nation after nation, the current generation outscores the last generation by some 9 to 20 IQ points. The gains are greatest on those tests often called the best measures of intelligence. Their size and speed dictate an environmental explanation. Flynn applied Jensen’s model. An environmental explanation meant putting the current generation within the top one-tenth of one percent of the last generation in terms of environmental quality. What was known to be true was shown to be impossible.

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.


  1. Szopen says:

    I’ve met so many idiots in my life, who went to the same school and who were astonishingly stupid even at the first year of school (when we were all 7), and I’ve observed so many differences between children before they go to school, so I don’t believe that genetical advantage is “modest” and merely pushes one to a different environment. This does not click with my experience.

  2. Kirk says:

    I have to agree with Szopen — to a degree.

    I don’t think we have even the beginnings of a true understanding of just what the hell we’re talking about when it comes to this quality called “intelligence”. We’ve also unfortunately decided to describe and ideate this poorly-defined and understood quality as being some kind of inherent virtue, and have ordered a lot of our society around this fundamentally flawed conception.

    Intelligence is as intelligence does. Are you more successful in your environment than another person? Then, for that environment, you’re more “intelligent” than someone else who isn’t as successful. Take the average Ashkenazic Jew, and dump him or her into the environment of the sub-Saharan African, and what you’re likely to get in fairly short order is going to be a small pile of human-derived lion poo. This is because that Ashkenazic Jew isn’t optimized to survive in situations that the average population of sub-Saharan Africans is, and likewise, the African ain’t likely to do well in the shtetl. This isn’t a pronouncement on their virtues, it’s simply a question of “fitness for purpose”.

    Because of our poor understanding of intelligence, we tend to think that the Ashkenazic Jew’s mastery of the written word (as a group generalization…) is superior to the African’s, because we’re evaluating the African on ground that the Ashkenazic Jew is extraordinarily well-adapted to… Of course, the African is going to wind up looking bad in that comparison. Were we to conduct our intelligence tests from standpoints that the African is well-adapted to, the Ashkenazic Jew is likely to wind up looking like an utter moron, because he or she can’t perform as well in the environment that the African is adapted to.

    Horses for courses. You could probably turn a St. Bernard into an outstanding field game dog with enough training, but the natural bent of the canine specialization in breed characteristics means that you’re generally never going to find a St. Bernard with the same natural gifts for upland game bird hunting that an English Setter possesses. At a very deep level, genetics matter–And, if you are going to insist on turning that St. Bernard into a game dog, you’d do well to acknowledge what that particular dog breed does possess in terms of genetic heritage, and adapt your training accordingly. And, just because that English Setter is a superior hunting dog, that doesn’t mean that the St. Bernard is a lesser creature, it just means that it’s not a really good choice as a hunting dog…

    You want a good lawyer, and can pick one only by their heritage? Your best bet is probably go through the phone book and find yourself the most Ashkenazic Jewish name you can, and hire him. However, don’t hire that guy to be your guide during your African safari dream vacation, either–Unless you’re planning on potting a few African tort claims.

    What we mistakenly think of as a virtue, intelligence, is more often an exemplar of “better adaptation to environment” than not. I have worked with some guys who did very, very well on the standard intelligence tests, yet who presented as useless dolts in the real world. Likewise, I’ve known some guys who were type-standardized as essentially morons by the intelligence tests, but who were in practical terms, geniuses with their hands and general problem-solving abilities.

    Whatever the hell we are talking about when we discuss this wil-o’-the-wisp concept of “intelligence”, it sure as hell is not the “virtue” we’re conceptualizing it as. The entire basis of our theoretically-meritocratic modern society is thus based on an inherently flawed conceptualization and understanding of a human quality that simply does not match well with how we try to use it in society.

    Some things just don’t translate well between environments. What works on the veldt doesn’t work well in the forest and towns of the North Eurasian landmass, and vice-versa.

    As well, we need to stop thinking of this crap as being the exhibition and demonstration of some kind of Darwinian virtue, when the plain fact is that there is no such thing. All there actually is? Adaptation. And, while that can cross-translate between environments fairly well, it can just as easily… Not.

  3. Bomag says:

    The entire basis of our theoretically-meritocratic modern society is thus based on an inherently flawed conceptualization and understanding of a human quality that simply does not match well with how we try to use it in society. (Kirk)

    You raise valid points, but intelligence is still one of the best metrics we have for predicting performance in a wide range of activities.

    Let us not invalidate something just because it isn’t 100 percent.

  4. Kirk says:

    My whole point is that we’re trying to use the metric we’ve developed for whatever it is that we’re assessing with so-called “intelligence tests” as a 100%, tried-and-true validated metric–And, it manifestly is no such thing.

    About all you can really tell from the tests we use these days is how well someone can score on that particular test at that particular time on that particular day. Past that? The results are spectacularly useless when it comes to being able to predict actual results out in the real world. I don’t know how many times I’ve run into complete idiots who had putative scores of 130 on the IQ tests, and who couldn’t pour piss out of a boot with written instructions attached to it. There’s whatever the hell we’re assessing with the IQ test, and then there’s real-world capability. Some cross-relationship may be present there, but it is damn spotty and highly unpredictable. Smartest guy I ever knew for being able to solve practical problems out on the ground was also someone the “intelligence tests” told us was a borderline moron. He just had issues with the written word, was all, but was hell on wheels with a wrench or another hand tool in his hands.

    Meanwhile, the tested-and-trained guys who were supposed to be doing his highly complex job? Couldn’t.

    The tests are flawed, period. They do not actually mean squat, when it comes to practical issues in day-to-day life, which is why you have so many academically-trained elite idiots who think they should be running the world, based on their test scores and grade point averages, while then screwing it up by the numbers. Just like the mania the Chinese developed for assessing everything based on Confucian principles and testing for that knowledge, the actual reality of the world is not captured very well in the tests, which leads to flawed selection and promotion of the people running things. Didn’t work for ancient China, ain’t working for us, and very badly needs to be rethought from first principles.

  5. James James says:

    Kirk, just because you know someone who did well at an IQ test but badly in life, that does not mean “The tests are flawed, period. They do not actually mean squat”. They are in fact strongly correlated with life success.

    Bomag: “You raise valid points, but intelligence is still one of the best metrics we have for predicting performance in a wide range of activities.”

    Correct. It’s wrong of Kirk to identify intelligence with evolutionary adaptedness. Fish are better adapted to living under the sea, but that’s not intelligence.

    Also, white people can move to Rhodesia and make more of a success of it than the natives, who are presumably better adapted to there. The Israelis made more of Israel than the previous inhabitants did. Even Sharm El Sheikh in Egypt only became a success when Israel took it over.

    Yudkowsky defines intelligence as the ability to “optimise across domains”, i.e. adaptability, the ability to quickly adapt to new environments. It’s the opposite of being adapted by evolution in a fixed sense.

  6. James James says:

    Is the concept “intelligence” conflating several different things? It appears not. The various measures of intelligence are correlated (the so-called g factor).

    The thing I don’t understand is how something qualifies as a measure of intelligence. If I come up with a new metric, and it doesn’t correlate with existing measures, does that disqualify it from being considered a measure of intelligence?

  7. Kirk says:

    James James:

    Strongly correlated with life success? LOL… Let’s just take a quick visit down to the local MENSA chapter, and see how many actual “success stories” we find there. What you’re actually going to find are a whole bunch of dysfunctional maladapts who think they’re ohsoverysmart, and who can’t pour piss out of a boot.

    I’m supposedly “highly intelligent”, based on test scores. I’m here to tell you, after a fair degree of “life exposure”, I have lost all faith in whatever it is they’re measuring with those things. Your examples of Israelis returning to Israel, and the whites going into what is now Zimbabwe are actually not quite what you think they are–It’s not the smarts of the Israelis or the whites in what was Rhodesia, what is mostly going on with both sets of circumstances is down to culture more than anything else. A more modern, entrepreneurial culture which takes a methodical scientific approach to things is naturally going to out-compete the locals, regardless of what the individuals may attain on their IQ tests.

    Indeed, it’s interesting that there are a lot of anthropologists who will tell you that the smartest people out there are to be found in the highlands of New Guinea, by many measures–And, those people are still living in a stone-age society. Jared Diamond is one anthropologist who’s written on the issue, and while I don’t agree with him on a lot of things, I’ll accept that he’s made an interesting argument that may or may not actually be backed up in the data.


    I’m still highly dubious of the value of these things, and I will continue to maintain that a high IQ score ain’t necessarily indicative of anything else than an ability to take that particular test on that particular date. Past that? The information the test results provides may or may not actually do you a damn bit of good, when it comes time to match an individual to a task.

    It has been my experience that the simpler the physical task, the harder actually doing that task will be for the individual who scores highly on those tests. The phrase “over-thinking things” is what you’ll observe, and you’ll also observe that the same task when given to someone who didn’t do as well in the testing oftentimes gets done more quickly and to a higher degree of quality.

    You want someone to explain quantum physics, get the guy who scores 160 on his IQ test. You want a warehouse organized? Better to pick the guy nearer 110. Put the certified genius in charge of organizing your storage areas, and you may never find anything ever again.

  8. Bomag says:


    There are many counter examples to any social science conclusion.

    The question remains: if you don’t like IQ tests, then what metric would you use that has anything close to its predictive power of performance in the modern world?

    Cyril Burt was feted for developing the IQ test to somewhat replace the English reliance on class and social status as a sorting mechanism.

  9. People seem to be talking past each other. Kirk, what the other commenters are referring to is the well-replicated finding that higher IQ is very closely correlated with educational performance, lifetime earning potential, marital and child-raising success, and a bunch of other measures I think most people would agree contribute to a well-lived life. It’s worth pointing out that all those studies find that the trend turns around at a certain point, and that the very, very brilliant (at least by IQ) tend to have a lot of trouble with quotidian reality.

    This observation hardly means that there aren’t plenty of outliers, or that IQ is a measure of personal worth or moral rectitude. It just means that, on average, a person with 120 IQ will have more success in business, education, and family life than someone with 100 IQ, who will be more successful than someone with 80 IQ.

  10. I also hasten to add that you’re entirely correct that those results are contextually dependent. No one, I think, is arguing that a 120 IQ westerner will do better if air-dropped naked into a desolate part of the Earth than an 80 IQ native of that environment All else being equal, though, a 120 IQ westerner would do better than an 80 IQ westerner with that situation.

    It’s worth point out that “all else being equal” in this thought experiment means that the 120 IQ westerner doesn’t have a brain chock full of ideas “so stupid only the educated believe them.”

  11. Kirk says:

    Gentlemen, what I’m railing against is the perverse use that these tests have been put to, and the entirely unjustified airs that those who do well on them have taken to flaunting, thinking that their ability to take tests and do well on them somehow substitutes for virtue, diligence, and morality.

    A meritocracy only has merit when it enables those of true merit to rise to the top. What we have actually got going on in our sadly diminished modern world is a system where the measure of man is in reality a mismeasure, and instead of the cream rising to the top, the pond scum is, having learned how to game the supposed system of meritocratic assessment and virtue.

    And, the roots of this go back to the assessment phase of the winnowing process used to select and advance those deemed to have merit. You select for the wrong thing, and you will never be able to rise above that erroneous selection–Which is the true crime of so-called “affirmative action” programs.

    I keep bringing up the Confucian analect where he discusses the “Rectification of Names”, because that goes to the root of what the hell is going wrong with our modern society in all too many aspects. When you don’t discuss things in properly defined and honest terms, persist in using euphemism, and do not address the true antecedents of our issues and problems? Solving them then becomes impossible by implication.

    Intelligence assessment is just an aspect of these root issues. We do not have a good and proper definition of what we are talking about, and cannot even effectively conceptualize what the hell we are talking about when we discuss it.

    As a thought experiment, consider the autistic “idiot savant” who does higher math tricks in his head that would confound many “normal” people, even those who are trained and proficient at mathematics. The savant spews forth correctly calculated numbers in a non-stop flow, akin to an electronic calculator or a computer.

    Is the idiot savant truly intelligent, when all he can do is calculate the numbers his handlers give him to work with? Or, is the intelligent one the handler, giving him the numbers and making use of the output?

    Moreover, can we call the savant intelligent, when, if left to his own devices, he’d likely kill himself in the outside world through sheer maladaptive behavior, walking in front of cars?

    And, of his handler, who cannot calculate cube roots in his head? Is he sub-intelligent, because of that, or is he a genius because he knows better than to walk into traffic?

    Extreme cases, yes, but they highlight the inadequate definitions we use discussing this. Rather than say that the IQ test assesses someone’s intelligence and “fitness for purpose” in general life, we ought to be discussing these things with clarity and honesty: Instead of saying that Joe is intelligent, we would be better to say that Joe does well on tests in the frozen and fixed world of paper and academics. Using that marker to assess the likelihood of his success in the wider world? Folly.

    Intelligence, if we are to truly come to grips with its true nature, needs must also be assessed in the outer world, where Joe would be required to perform dynamically in unfixed concrete situations.

    We’ve abstracted things too far, with how we’re assessing this aspect of our humanity. Because of that, distortions have crept in, and those distortions are warping academia and society in general. You want a true evaluation of someone’s intelligence, you needs must include a range of things past paper calculations or abstract problem-solving in the classroom environment. A proper test that assessed the full range of what should be properly defined as true intelligence would need to encompass a number of things outside the realm of the abstract, such as solving concrete puzzles in spatial relationships, and between other human beings.

    I cannot call you a genius-level intellect if you can’t effectively work well with others, and manage to alienate everyone around you every time you open your mouth–And, to say that someone who does that is intelligent…?

    You’re working with a very inadequate and essentially useless definition of the term.

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