The NY Times reviews a new IQ book

If books challenging religious belief are judged to ruffle feathers, than those investigating differences in IQ across human populations–whatever conclusions these draw or invite–can fairly be said to bite the heads off live chicken in one powerful Ozzy Osbourne-style jaw snap. They are never uncontroversial.
In his review of a book by University of Michigan psychologist Richard E. Nisbett, “Intelligence and How to Get It,” Jim Holt states that the author “offers a meticulous and eye-opening critique of hereditarianism.” He refers to Nisbett’s “forceful marshaling of the evidence, much of it recent … which stresses the importance of nonhereditary factors in determining I.Q.” and elaborates on Nisbett’s central claim, in which he breaks ranks from his predecessors in the field:

Nisbett bridles at the hereditarian claim that I.Q. is 75 to 85 percent heritable; the real figure, he thinks, is less than 50 percent. Estimates come from comparing the I.Q.’s of blood relatives — identical twins, fraternal twins, siblings — growing up in different adoptive families. But there is a snare here. As Nisbett observes, “adoptive families, like Tolstoy’s happy families, are all alike.” Not only are they more affluent than average, they also tend to give children lots of cognitive stimulation. Thus data from them yield erroneously high estimates of I.Q. heritability. (Think: if we all grew up in exactly the same environment, I.Q. differences would appear to be 100 percent genetic.) This underscores an important point: there is no fixed value for heritability. The notion makes sense only relative to a population. Heritability of I.Q. is higher for upper-class families than for lower-class families, because lower-class families provide a wider range of cognitive environments, from terrible to pretty good.

Holt notes that Nisbett uses basic statistics to take apart long-held notions that, for example, measured differences in IQ between U.S. blacks and Americans of predominantly European descent (a gap which has shrunk from 15 point to 9.5 in just 30 years), differences between East Asians and “white” Americans, and the superiority of Ashkenazi Jews are rooted in genetics.
Holt offers his own editorial comments at the end of his review:

Even if I.Q. inequality is inevitable, it may eventually become irrelevant. Over the last century, for reasons that aren’t entirely clear, I.Q. scores around the world have been rising by three points a decade. Some of this rise, Nisbett argues, represents a real gain in intelligence. But beyond a certain threshold — an I.Q. of 115, say — there is no correlation between intelligence and creativity or genius. As more of us are propelled above this threshold — and, if Nisbett is right, nearly all of us can be — the role of intelligence in determining success will come to be infinitesimal by comparison with such “moral” traits as conscientiousness and perseverance. Then we can start arguing about whether those are genetic.

  1. #1 by uk superman on March 30, 2009 - 12:16 pm

    i’ve studied in my free time much on learning theory, professionalism and expertise from athletes to mathematicians and frankly i would be flabbergasted if people can’t study and practise to improve iq scores.

  2. #2 by Snowbird on March 30, 2009 - 9:38 pm

    IQ was developed by Binet to determine who wouldn’t do well in school. In this respect, it does a very good job. As to who will do well…not so much. The correlation between IQ and success in life is even more tenuous.
    Bottom line – IQ is a canard, and the quicker we put the myth that it actually measures real intelligence, the better. Just remember that Richard Feynman’s IQ was within 2 standard deviations, but this guy was an absolute genius in every sense of the word.

  3. #3 by jay on March 30, 2009 - 9:53 pm

    I recognize that there is a real danger in responding to a summary, but even if adoptive families tend to be more supportive and consistent (not sure that is really true, I’d really like to see evidence), the problem is that the difference between identical twins and other siblings in adoptive situations is still markedly different. Even if all adoptive families were identical, that would not explain why monozygotic twins score very close and others do no.

  4. #4 by Ann on April 1, 2009 - 11:21 am

    Here is a quote from child psychologist Adam Cox which talks about IQ and giftedness from an interesting perspective:
    “The most useful perspective of excellence is one that resonates with the tangible needs of our lives. After all, if talent is not in some form useful, both to an individual and a society, it holds no value. Yet when we look at those who have the most to offer others, we may notice a conundrum: being traditionally gifted– “high IQ,” “athletic,” “artistic,” etc.-does not guarantee the translation of those gifts into tangible and positive contributions.
    What if we were to consider the possibility that parents and teachers who struggle to define more amorphous gifts in children may be intuiting something very real? And what if we could distinguish those gifts that were exceptionally valuable, and provide a roadmap for developing them in all kinds of kids? When I talk about executive function and capability, I’m trying to move you toward this idea….
    Virtually all previous attempts to discuss exceptionality have opted to view the significant achievements of young people with a decidedly academic lens. Certainly, these gifts deserve acknowledgement – just not all the acknowledgement.
    The twentieth century celebrated a very hierarchical idea of cognitive/creative excellence, encapsulated by the near idolatry of popular figures like Einstein, Freud, and Picasso. Overall, “genius” was considered to be masculine, white, hierarchical, and measurable. Today, excellence swims much closer to its beneficiaries. In fact, this proximity may unintentionally obscure important contributions – to take for granted those young minds we interact with daily that bind achievement to pressing human needs…. kids I often refer to as Rising Stars – because the value of their “gifts” is on the rise. It’s not so much that their gifts have never been recognized, but in most cases they are not the kids we have traditionally thought of as gifted. I believe that concept should be anchored by tangible contribution rather than one’s IQ. And as in other areas, I have a strong bias toward social relevance.
    The names I have assigned to these seven groups of kids: Navigators · Magicians · Sparkplugs · Translators · Locomotives · Rangers · Conductors”
    He then discusses a framework of attributes of excellence.
    So in a way, the question of hereditianarism, IQ across race and genders, is an old discussion whose time may be passing. In the age of Obama, perhaps we have too much evidence of achievement across gender and racial lines to worry about a construct that was only intended as a tool to target narrow abilities within an academic setting. Nisbett can dismantle the argument, but now we need to move on to new ways of framing the question.
    As someone who works with special needs children, I may have a different perspective than most. But to still be talking about “IQ” seems about a relevant as talking about beta vs. vhs – it’s over.

  5. #5 by Gingerbaker on April 7, 2009 - 4:26 pm

    The reason why IQ does not have simple hereditary characteristics like some aspects of athleticism or height, weight, baldness (curses!) is that the brain is a uniquely plastic organ.
    If Alfred Einstein had an illicit love child with, say, Hillary Clinton, (shudder) the poor child would still be a moron if raised by Josef Fritzl. (Yet still, I wager, be smart enough not to answer questions about an affair with an intern while under oath :D)
    Correspondingly, a child from parents of average intelligence would likely significantly outscore them if his brain was properly stimulated during the correct years of development.
    I’m having difficulty understanding why the idea that environmental influences would play a large role in IQ scores is controversial.

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