10 ms·

Flynn’s IQ

197 points by tortilla 14y ago

tokenadult 14y ago
Links to information about the book under review, Are We Getting Smarter?: Rising IQ in the Twenty-First Century by James R. Flynn: http://www.cambridge.org/gb/knowledge/isbn/item6835805/?site_locale=en_GB http://www.cambridge.org/gb/knowledge/isbn/item6835805/?site... http://www.amazon.com/Are-We-Getting-Smarter-Twenty-First/dp/1107609178 http://www.amazon.com/Are-We-Getting-Smarter-Twenty-First/dp... (The three expert reviewers shown on Amazon are all very impressive researchers on human intelligence in their own right, so their joint endorsement of Flynn's book carries a lot of weight for people like me who follow the research.) Here is what Arthur Jensen said about Flynn back in the 1980s: "Now and then I am asked . . . who, in my opinion, are the most respectable critics of my position on the race-IQ issue? The name James R. Flynn is by far the first that comes to mind." Modgil, Sohan & Modgil, Celia (Eds.) (1987) Arthur Jensen: Concensus and Controversy New York: Falmer. AFTER EDIT: Replying to another top-level comment: I don't understand how anyone could not have an emotional response being told 'your IQ is x'. People have emotional responses to most statements about themselves that they think are overall evaluations. Some of those emotional responses are more warranted than others. Devote some reading time to the best literature on IQ testing (besides the book under review in this thread, that would include Mackintosh's second edition textbook IQ and Human Intelligence http://www.amazon.com/IQ-Human-Intelligence-Nicholas-Mackintosh/dp/0199585598/ http://www.amazon.com/IQ-Human-Intelligence-Nicholas-Mackint... and the Sternberg-Kaufman Cambridge Handbook of Intelligence, http://www.amazon.com/Cambridge-Handbook-Intelligence-Handbooks-Psychology/dp/052173911X/ http://www.amazon.com/Cambridge-Handbook-Intelligence-Handbo... both recently published). Any of these books will help readers understand that IQ tests are samples of learned behavior and are not exhaustive reports on an individual's profile of developed abilities. AFTER ANOTHER EDIT: Discussion of heritability of IQ, a reliable indicator of how much discussants read the current scientific literature on the subject, has ensued in some other subthreads here. Heritability of IQ has nothing whatever to do with malleability (or, if you prefer this terminology, controllability) of human intelligence. That point has been made by the leading researchers on human behaviorial genetics in their recent articles that I frequently post in comments here on HN. It is a very common conceptual blunder, which should be corrected in any well edited genetics textbook, to confuse broad heritability estimates with statements about how malleable human traits are. The two concepts actually have no relationship at all. Highly heritable traits can be very malleable, and the other way around. Johnson, Wendy; Turkheimer, Eric; Gottesman, Irving I.; Bouchard Jr., Thomas (2009). Beyond Heritability: Twin Studies in Behavioral Research. Current Directions in Psychological Science, 18, 4, 217-220 http://people.virginia.edu/~ent3c/papers2/Articles%20for%20Online%20CV/Johnson%20(2009).pdf http://people.virginia.edu/~ent3c/papers2/Articles%20for%20O... is an interesting paper that includes the statement "Moreover, even highly heritable traits can be strongly manipulated by the environment, so heritability has little if anything to do with controllability. For example, height is on the order of 90% heritable, yet North and South Koreans, who come from the same genetic background, presently differ in average height by a full 6 inches (Pak, 2004; Schwekendiek, 2008)." Another interesting paper, Turkheimer, E. (2008, Spring). A better way to use twins for developmental research. LIFE Newsletter, 2, 1-5 http://people.virginia.edu/~ent3c/papers2/Articles%20for%20Online%20CV/Turkheimer%20(2008).pdf http://people.virginia.edu/~ent3c/papers2/Articles%20for%20O... admits the disappointment of behavioral genetics researchers. "But back to the question: What does heritability mean? Almost everyone who has ever thought about heritability has reached a commonsense intuition about it: One way or another, heritability has to be some kind of index of how genetic a trait is. That intuition explains why so many thousands of heritability coefficients have been calculated over the years. Once the twin registries have been assembled, it’s easy and fun, like having a genoscope you can point at one trait after another to take a reading of how genetic things are. Height? Very genetic. Intelligence? Pretty genetic. Schizophrenia? That looks pretty genetic too. Personality? Yep, that too. And over multiple studies and traits the heritabilities go up and down, providing the basis for nearly infinite Talmudic revisions of the grand theories of the heritability of things, perfect grist for the wheels of social science. "Unfortunately, that fundamental intuition is wrong. Heritability isn’t an index of how genetic a trait is. A great deal of time has been wasted in the effort of measuring the heritability of traits in the false expectation that somehow the genetic nature of psychological phenomena would be revealed. There are many reasons for making this strong statement, but the most important of them harkens back to the description of heritability as an effect size. An effect size of the R2 family is a standardized estimate of the proportion of the variance in one variable that is reduced when another variable is held constant statistically. In this case it is an estimate of how much the variance of a trait would be reduced if everyone were genetically identical. With a moment’s thought you can see that the answer to the question of how much variance would be reduced if everyone was genetically identical depends crucially on how genetically different everyone was in the first place." The review article "The neuroscience of human intelligence differences" by Deary and Johnson and Penke (2010) relates specifically to human intelligence: http://www.larspenke.eu/pdfs/Deary_Penke_Johnson_2010_-_Neuroscience_of_intelligence_review.pdf http://www.larspenke.eu/pdfs/Deary_Penke_Johnson_2010_-_Neur... "At this point, it seems unlikely that single genetic loci have major effects on normal-range intelligence. For example, a modestly sized genome-wide study of the general intelligence factor derived from ten separate test scores in the cAnTAB cognitive test battery did not find any important genome-wide single nucleotide polymorphisms or copy number variants, and did not replicate genetic variants that had previously been associated with cognitive ability[note 48]." The review article Johnson, W. (2010). Understanding the Genetics of Intelligence: Can Height Help? Can Corn Oil?. Current Directions in Psychological Science, 19(3), 177-182 http://apsychoserver.psych.arizona.edu/JJBAReprints/PSYC621/Johnson%20Current%20Directions%20Psych%20Science%202010%20(G%20and%20E%20in%20IQ).pdf http://apsychoserver.psych.arizona.edu/JJBAReprints/PSYC621/... looks at some famous genetic experiments to show how little is explained by gene frequencies even in thoroughly studied populations defined by artificial selection. "Together, however, the developmental natures of GCA and height, the likely influences of gene–environment correlations and interactions on their developmental processes, and the potential for genetic background and environmental circumstances to release previously unexpressed genetic variation suggest that very different combinations of genes may produce identical IQs or heights or levels of any other psychological trait. And the same genes may produce very different IQs and heights against different genetic backgrounds and in different environmental circumstances."
- nostrademons 14y ago
  "did not find any important genome-wide single nucleotide polymorphisms or copy number variants, and did not replicate genetic variants that had previously been associated with cognitive ability" It's worth making another point here - just because there is no single gene for a trait does not make in unheritable, and just because a trait is genetic does not mean there is a single gene for it. Eye color, for example, is clearly a genetic trait, but may be controlled by as many as 16 different genes. Race is also genetic, but really is shorthand for variation in hundreds, maybe thousands of genes. It's well-established that intelligence is polygenic. That doesn't mean it's not genetic - if everybody had the same genes, ~80% of the variation in intelligence would be eliminated. It also doesn't mean that there's a single genetic switch we can throw to design a master race of human geniuses. It means exactly what it says: that there are some combination of genes that interact together to produce ~70-90% of the variance in the measured quantity that we label "intelligence".
  - eevilspock 14y ago
    "Race is also genetic, but really is shorthand for variation in hundreds, maybe thousands of genes." There's a subtlety in your statement that I think will be lost on too many people, even more so given the juxtaposition with the statement about eye color. So at the risk of sounding pedantic... Race is not a trait like eye color. Variations in the human gene pool are not evenly distributed geographically or across ethnic groups for a number of historical reasons. Many of these genes manifest in our physical appearance. But there is no countable number of races. Dividing humanity into 3, 4, 5 or even a hundred races is totally artificial. All you have to do is walk from Europe to SE Asia, or Europe to Africa via the middle east and you will see a gradual change, a gradient for each of the observed physical differences. So description of "race" as a "shorthand" is spot on. Sadly it is a poor shorthand because most everyone conceive of race as discrete types of humans. Sigh.
    - nostrademons 14y ago
      If you have a broad enough cultural background, eye color is not a simple discrete trait either. I was eavesdropping on the conversation behind me on the bus today: "What color would you describe your eyes as?" a guy asks. "Green-ish. Something like that," a girl answers. "Good, you didn't say hazel. A bunch of people would've called them that." And then followed a whole long discussion about how you can basically perform hierarchical agglomerative clustering on humanity's words for colors, if you follow the words linguistically back through a few thousand years. Apparently the first split happened between light & dark, and then broad colors like "blue/green" (as a single color) split off, and then modern languages broke blue & green into separate colors. Some folks break them down even further, into "cerulean" and "turquoise" and "aquamarine" and "royal blue". I've heard (from sources other than the bus conversation) that women actually have significantly more color words in their vocabulary than men do; they make distinctions where men don't. So eye color is a shorthand too. Some people just say "light" or "dark". Others say "brown" or "blue". Still others will break it down into "black", "brown", "blue", "green", and "hazel". Once in a while you'll get a poetic type who'll say "Eyes the color of a roiling sea, as you catch the last glimpse of sunlight before a storm rolls in." Bringing it back on topic, intelligence is a shorthand as well. It stands for a bunch of directly observable characteristics, but which characteristics vary depending on who you ask. Some people think an intelligent person is one with a high IQ who always does well on standardized tests. Others think it's someone who accomplishes great things in the intellectual realm, another Tesla or Einstein. Still others define it as a talent, and claim there're multiple intelligences, each in one desirable realm. Perhaps the meta-lesson isn't about race or eye color or heritability at all, it's to drill down and ask what we actually mean by such broad characteristics. When you make a statement such as "IQ has a heritability of 0.8", you're making a very specific statistical assertion (though even that's not ironclad: which IQ test?). But whether that lines up with the statement of "Intelligence is largely genetic" depends on what you mean by "intelligence" and "genetic", both of which are very broad concepts that hide a lot of subtlety.
marquis 14y ago
Am I the only one who refuses to take an IQ test? I hate being tested - especially with a time limit, I rarely play games (chess and logic puzzles being the exception) but above all I don't understand how anyone could not have an emotional response being told 'your IQ is x'.
- sp332 14y ago
  Did you have an emotional response when you learned that you could only hold "7, plus or minus 2" things in your short-term working memory? Or when you found out what your adult height was going to be for the rest of your life?
  - marquis 14y ago
    >Did you have an emotional response when you learned that you could only hold "7, plus or minus 2" things in your short-term working memory? Well, no - because I could use tools to extend that. And it's not about insecurity, as I'm quite comfortable with myself and my brain. I just don't see it as being a valuable reference. However, I know if I had a number I'd start comparison-shopping and I might feel either elated (if high) or depressed (if low). Is anyone here, if you have had an IQ test, honestly prepared to say that you didn't or wouldn't be curious about what that meant and that it wouldn't affect how you viewed yourself? I just don't need to know. I guess that for me, as long as there isn't a 'goal' or a 'fence', the sky's the limit.
    - mikeash 14y ago
      You can extend your effective IQ using tools as well. I bet your IQ as tested while you have access to an internet-connected computer would be way higher than your IQ as tested on a closed-book test.
      - esrauch 14y ago
        I doubt it, unless you could find a cheat sheet for the test you are taking. It's not like the test is asking about information, facts or calculations; what would you type in to Google to answer a question like this? http://upload.wikimedia.org/wikipedia/commons/thumb/0/0f/RavenMatrix.svg/220px-RavenMatrix.svg.png http://upload.wikimedia.org/wikipedia/commons/thumb/0/0f/Rav...
kevinpet 14y ago
I have no idea what is the author of the articles opinion, and what is from the book being reviewed. I'm not even sure what the title of the book being reviewed is.
- agscala 14y ago
  I'm glad I wasn't the only one completely confused. I have no idea what he was trying to say, I can't imagine what his book is like.
ilaksh 14y ago
So the vast majority of people misunderstand intelligence, at least as measured by IQ tests, as being a limiting factor for performance and potential, while it is actually just a measurement of current abilities. > the penultimate chapter is a list of 14 examples in which science has failed because of social blindness. This carries through more broadly and generally to the application of many incorrect fundamental assumptions to the design of our institutions, which consistently fail because of the resulting flawed structures.
- bearmf 14y ago
  It is a limiting factor for many tasks, even such "simple" tasks as basic algebra and calculus. A lot of people fail at math simply because they do not have enough brainpower.
  - DiabloD3 14y ago
    No, they fail at math because they have never learned how to use their brainpower effectively. The difference between geniuses and everyone else, from my experiences, are not any fundamental difference in their brain wiring, but that they learned how to better focus what brainpower they do have, Its like the difference between a guy who gives 120% every day but his work, taken individually, is mediocre vs a guy who gives his 1% but his 1% is the Nobel prize winning work of his field... the guy who gives his 120% day in and day out is a smarter man. Ironically, an IQ test will not say much about either of them. The 120% guy might score lower than the 1% man by 10 or 15 points, but the 120% guy, if he were, say, a researcher or inventor, would be spending day in and day out finding thousands of ways that don't work just so he can find one that does. The 120% man learned how to focus the skills he does have and learned how to apply them well; of the two, I'd hire him over the 1% man, Nobel or not. The few super geniuses that history remembers (such as Tesla) had both: 120% work ethic combined with a brilliant mind. These people are rare, but every single person no matter their racial or religious background has the ability to become that kind of person to.... they just never learn how to.
    - victorhn 14y ago
Claudus 14y ago
The Flynn effect tends to be used to support the feeling that intelligence isn't something you're born with. People who think that intelligence is innate will refer to the "g factor". http://en.wikipedia.org/wiki/G_factor_%28psychometrics%29 http://en.wikipedia.org/wiki/G_factor_%28psychometrics%29 The racist (technically speaking) and controversial Jean Rushton believes that "gains in IQ over time (the Lynn-Flynn effect) are unrelated to g". What's really going on with discussions like this is that humanity seems to have come to the conclusion that "smarter is better". Intelligence almost certainly exists, but is quite difficult to quantify exactly, and is further complicated by the fact that people resent others who are "better" than them. Given that there is a genetic component to intelligence to a certain degree, race becomes a factor and leads to a line of inductive reasoning that makes people uncomfortable: 1) Smarter is better 2) Intelligence is genetic 3) Race determines genetics 4) One race is better than another 5) Hitler was right (or other outrageous conclusion) As far as I can tell when you see terms like "g factor", "Flynn effect", "multiple intelligences", "crystallized intelligence", "fluid intelligence", "cultural fair IQ tests", "The bell curve"... people are really secretly arguing about one race or sex being smarter than the other, or not.
- bearmf 14y ago
  Points 1-2 are valid, though intelligence is not entirely genetic. Your points 3-5 are completely wrong. Genetics determines race, not the other way around. Points 4 and 5 are just meaningless "racist" phrases, not statements in a line of reasoning.
  - ajross 14y ago
    It may be semantics, but genetics certainly does not determine "race" alone. If it did, "african american" and "hispanic" wouldn't exist as "races". The idea of classifying people like that doesn't work genetically. First, people have been interbreeding like rabbits throughout history; there are no "pure" stocks anywhere. And more importantly, the amount of genetic variation between any two individuals from the same "race" is much higher than it is, statistically, between the aggregate genetic profiles of distinct "races". Basically, "race" is a cultural distinction. It's a label we apply as a proxy for other stuff (usually cultural). Scientists (well, except anthropologists studying that cultural stuff) don't use it, and for good reason.
bearmf 14y ago
And still IQ is very good at predicting various life outcomes: probabliity of being arrested, income, number of children. Group differences in IQ do exist, and Flynn effect does not make them go away. Flynn effect increases scores across the board, it does not equalize different groups. Black people in US have lower average IQ than white people do, Asian people have higher average IQ. The reasons for this are many, but genetics certainly comes into play: IQ is heritable. Trying to explain away group differences by "culture" is mostly bad science - trying to make the facts fir your desired conclusions.
- paranoiacblack 14y ago
  No, I agree with this. There was obviously nothing wrong eugenics movement 100 years ago. And obviously minorities get arrested more, have lower income, and a lot of children because of their extremely low IQ as opposed other social forces. See the difference is you are talking out of your ass, whereas Flynn has a book filled with verifiable statistics.
- jeremyjh 14y ago
  And yet its clear you did not read the article.
- Steko 14y ago
  Key takeaway from the article: Flynn’s interpretation overturns one of the most dangerous myths of IQ research — that blacks have been shown to be fundamentally less intelligent than whites. With what seems to me to be a series of cast-iron statistical analyses, he shows that this has, in fact, never been proved ... What the evidence actually shows is that racial differences, once all external factors are removed (primarily the social and cultural context of the testees), seem to be almost undetectably small.
  - esrauch 14y ago
    I personally don't believe there to be real genetic differences in this context, but that conclusion doesn't seem to preclude there being differences in social and cultural predispositions for different races, then there would still be a direct causal relationship between race and intelligence.
Dylan16807 14y ago
These people aren’t any less intelligent than the researcher — their minds just work differently. They focus on the practicalities they know rather than hypothetical possibilities. That's going to need some explanation. First off, I can see how the question itself is abstract, about a place they have never been, but "no camels" sounds extremely concrete to me. Second, how is ignoring information anything other than a lapse in intelligent thought?
- paranoiacblack 14y ago
  You're missing the point. If you ask someone a question that expects them to think in a way foreign to them, it does not say anything about their intelligence if they have difficulty approaching it. Think of the old "analytical" thinking questions companies used to give out like "how many golf balls can you fit in a bus", "how many high schools are there in America", etc. Now, I'm not the smartest person but my peers and bosses consider me to be highly intelligent. When I first heard these questions, I was completely stumped. I mean, I've never really taken public transportation and I don't know really have a good idea of how many students go to a typical high school or even how large America is, so how was I supposed to know? However, the population cutoffs for high schools and the size of buses and golf balls are very concrete and well known. Does this show a lapse in my intelligence?
  - Dylan16807 14y ago
    The examples you gave only have issues in not knowing the sizes of things. They have nothing to do with thinking in 'foreign ways'. If I show someone a golf ball and ask how many fit into a wagon I expect them to at least say "a lot". If they have math skills then I expect an order-of-magnitude estimate. If you don't know the sizes, then the test-maker has failed you. If you know the sizes and still can't answer, then yes it is a lapse in intelligence. Can you give me an example of a problematic question that isn't caused by using unfamiliar nouns?
    - majormajor 14y ago
      This isn't exactly the same thing as "no camels" but it feels like it's in a similar completely-out-of-your-frame-of-reference ballpark: People thought all-touchscreen devices with no keypad would be useless as phones—they didn't see how the inconvenience of punching numbers in on a touch screen without tactile feedback could be greatly outweighed by other stuff the large touchscreens would end up enabling. Yet it would be ridiculous to say the reason anyone failed to initially grasp the possibilities was a lack of intelligence. I imagine that being told "there are no camels in Germany; how many camels are in this German city?" simply sounded ridiculous to the rural Russians. And so I assume that with no background in abstract reasoning or "word problems" where you're supposed to rely on just the information presented in the problem, they fell back on what they knew about cities: they're places with camels. Imagine if someone came to you from another country and said something like "we don't have people in our cities. But Atlantis is our biggest city. So how many people do you think live there?" It would sound meaningless.
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- corporalagumbo 14y ago
  Christopher Langan.
- hebz0rl 14y ago
  http://en.wikipedia.org/wiki/Christopher_Langan http://en.wikipedia.org/wiki/Christopher_Langan
- deleted 14y ago
  [deleted]
Alex3917 14y ago
"contrary to widespread assumptions, no clear link between nutrition and IQ has been found." Someone call up Paul Krugman and tell him that iodine deficiency doesn't actually cause mental retardation.
pixelcort 14y ago
OT: Just me, or does browser zoom not seem to increase font size for this page in Safari and Chrome?
- peregrine 14y ago
  Super annoying, I had to read it in Instapaper just to cope.
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aaron695 14y ago
To not know the answer to "there are no camels in Germany so how many camels do they think there are in B, a specific German city? " is not a cultural difference, to think that other cultures are seriously that dumb is more a statement on ones self than anything else. This is similar to statements engineers sometimes make that the Chinese are good copiers but can't innovate. No, cultures are the same as everyone else. They have humour, art and like to tinker and have in jokes. If they don't publicly innovate it's more likely it's not economical in that environment yet. The fact 'camels' was used has strong undertones to me, if this was an actually a study I'd be interested to know.
- eru 14y ago
  > No, cultures are the same as everyone else. They have humour, art and like to tinker and have in jokes. Oh, cultures share lots of features. But I've been in a few. Even countries as geographically close as Britain and Germany have quite a few differences.
Aloisius 14y ago
Wait, people take IQ tests seriously? Really? I was tested twice when I was in second grade, the first time by a psychologist in a class setting and the second time one-on-one to verify the first. I tested quite high, but even then I knew I wasn't noticeably smarter than others; I just test particularly well. Frankly, it cracks me up when someone refers to their IQ seriously or boasts about being in Mensa. Other than testing for mid-to-high level mental retardation, subjectively, IQ tests seem to be terrible at measuring actual brilliance.
- ghshephard 14y ago
  I don't know about "IQ tests seem to be terrible at measuring actual brilliance." - Some of the components of IQ tests are fantastically accurate. I can't read maps, I can't put a monitor back in it's box. And I score very poorly on the pattern assessment components of IQ tests. I guess you might say I'm "mid-to-high level mentally retarded on pattern assessment." Likewise, I have a friend who is world class _stellar_ at putting Monitors back in complicated styrofoam packing and into boxes (Seriously - his ability in this task is amazing) - and he tests off the chart on the pattern recognition component of IQ tests. So - I can, based on the admittedly small anecdotal sample of n=2, suggest that there is strong predictive power of at least some elements of the IQ tests.
  - aik 14y ago
    I think the main point is that IQ measures some sort of current fluid intelligence. It doesn't measure other types of intelligence, and most importantly it doesn't measure potential. So the blanket concept of it defining someone's common-understanding-of-"intelligence" is flawed to the extent of it being a pointless or harmful measure in many of cases.
    - ghshephard 14y ago
      What I'm arguing is the opposite - that the IQ test actually is precisely a measure of potential in various abstract areas. Whether you do anything with that potential, or how you develop it (as, in the case of my friend, who is a savant in putting Monitors back into styrofoam boxes) - is a function of resources, opportunity, and interest. Flynn goes further, and suggests that the society and culture that you grow up in, also enhance your ability to execute on IQ tests. The genetic potential (obviously?) hasn't changed, but the environment has shifted such that our "actuated" IQ has increased as we practice more often in abstract tests.
pud 14y ago
Unrelated to the content, when I use Command-plus to increase the font size on this blog (in Chrome, at least), the font doesn't grow. Which means I can't read it, because my eyes suck.
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pmb 14y ago
Two wonderful companions to this article are "Thinking Intelligence is Innate Makes You Stupid" http://lemire.me/blog/archives/2007/12/03/thinking-intelligence-is-innate-makes-you-stupid/ http://lemire.me/blog/archives/2007/12/03/thinking-intellige... and (especially) Cosma Shalizi's article on the malleability and heritability of IQ http://cscs.umich.edu/~crshalizi/weblog/520.html http://cscs.umich.edu/~crshalizi/weblog/520.html
mistercow 14y ago
>For this to happen, evolution would have had to have accelerated to light speed. What? No... no. There are plenty of ways that intelligence could have dramatically increased since the '30s without any evolutionary effects.
avatarlite 14y ago
Anyone interested in this topic should read the primary research papers. The pattern of differences in IQ test answers between generations is not congruent with the pattern of differences between individual who do better and worse on average within generations -- at least according to the few studies which have looked at this question. For this reason, we can infer that the generational changes in IQ test scores are not changes in the same underlying factor that causes differences in performance within a generation. If we call the factor that causes within-generation differences in IQ test scores intelligence, then what differs between generations isn't intelligence. In other words, the Flynn effect is something other than what it might appear at first glance. It's still something of a mystery. Multi-group confirmatory factor analysis can be used to demonstrate this, or you can just look at the correlation matrices.

197 points by tortilla 14y ago

Links to information about the book under review, Are We Getting Smarter?: Rising IQ in the Twenty-First Century by James R. Flynn: http://www.cambridge.org/gb/knowledge/isbn/item6835805/?site_locale=en_GB http://www.cambridge.org/gb/knowledge/isbn/item6835805/?site... http://www.amazon.com/Are-We-Getting-Smarter-Twenty-First/dp/1107609178 http://www.amazon.com/Are-We-Getting-Smarter-Twenty-First/dp... (The three expert reviewers shown on Amazon are all very impressive researchers on human intelligence in their own right, so their joint endorsement of Flynn's book carries a lot of weight for people like me who follow the research.) Here is what Arthur Jensen said about Flynn back in the 1980s: "Now and then I am asked . . . who, in my opinion, are the most respectable critics of my position on the race-IQ issue? The name James R. Flynn is by far the first that comes to mind." Modgil, Sohan & Modgil, Celia (Eds.) (1987) Arthur Jensen: Concensus and Controversy New York: Falmer. AFTER EDIT: Replying to another top-level comment: I don't understand how anyone could not have an emotional response being told 'your IQ is x'. People have emotional responses to most statements about themselves that they think are overall evaluations. Some of those emotional responses are more warranted than others. Devote some reading time to the best literature on IQ testing (besides the book under review in this thread, that would include Mackintosh's second edition textbook IQ and Human Intelligence http://www.amazon.com/IQ-Human-Intelligence-Nicholas-Mackintosh/dp/0199585598/ http://www.amazon.com/IQ-Human-Intelligence-Nicholas-Mackint... and the Sternberg-Kaufman Cambridge Handbook of Intelligence, http://www.amazon.com/Cambridge-Handbook-Intelligence-Handbooks-Psychology/dp/052173911X/ http://www.amazon.com/Cambridge-Handbook-Intelligence-Handbo... both recently published). Any of these books will help readers understand that IQ tests are samples of learned behavior and are not exhaustive reports on an individual's profile of developed abilities. AFTER ANOTHER EDIT: Discussion of heritability of IQ, a reliable indicator of how much discussants read the current scientific literature on the subject, has ensued in some other subthreads here. Heritability of IQ has nothing whatever to do with malleability (or, if you prefer this terminology, controllability) of human intelligence. That point has been made by the leading researchers on human behaviorial genetics in their recent articles that I frequently post in comments here on HN. It is a very common conceptual blunder, which should be corrected in any well edited genetics textbook, to confuse broad heritability estimates with statements about how malleable human traits are. The two concepts actually have no relationship at all. Highly heritable traits can be very malleable, and the other way around. Johnson, Wendy; Turkheimer, Eric; Gottesman, Irving I.; Bouchard Jr., Thomas (2009). Beyond Heritability: Twin Studies in Behavioral Research. Current Directions in Psychological Science, 18, 4, 217-220 http://people.virginia.edu/~ent3c/papers2/Articles%20for%20Online%20CV/Johnson%20(2009).pdf http://people.virginia.edu/~ent3c/papers2/Articles%20for%20O... is an interesting paper that includes the statement "Moreover, even highly heritable traits can be strongly manipulated by the environment, so heritability has little if anything to do with controllability. For example, height is on the order of 90% heritable, yet North and South Koreans, who come from the same genetic background, presently differ in average height by a full 6 inches (Pak, 2004; Schwekendiek, 2008)." Another interesting paper, Turkheimer, E. (2008, Spring). A better way to use twins for developmental research. LIFE Newsletter, 2, 1-5 http://people.virginia.edu/~ent3c/papers2/Articles%20for%20Online%20CV/Turkheimer%20(2008).pdf http://people.virginia.edu/~ent3c/papers2/Articles%20for%20O... admits the disappointment of behavioral genetics researchers. "But back to the question: What does heritability mean? Almost everyone who has ever thought about heritability has reached a commonsense intuition about it: One way or another, heritability has to be some kind of index of how genetic a trait is. That intuition explains why so many thousands of heritability coefficients have been calculated over the years. Once the twin registries have been assembled, it’s easy and fun, like having a genoscope you can point at one trait after another to take a reading of how genetic things are. Height? Very genetic. Intelligence? Pretty genetic. Schizophrenia? That looks pretty genetic too. Personality? Yep, that too. And over multiple studies and traits the heritabilities go up and down, providing the basis for nearly infinite Talmudic revisions of the grand theories of the heritability of things, perfect grist for the wheels of social science. "Unfortunately, that fundamental intuition is wrong. Heritability isn’t an index of how genetic a trait is. A great deal of time has been wasted in the effort of measuring the heritability of traits in the false expectation that somehow the genetic nature of psychological phenomena would be revealed. There are many reasons for making this strong statement, but the most important of them harkens back to the description of heritability as an effect size. An effect size of the R2 family is a standardized estimate of the proportion of the variance in one variable that is reduced when another variable is held constant statistically. In this case it is an estimate of how much the variance of a trait would be reduced if everyone were genetically identical. With a moment’s thought you can see that the answer to the question of how much variance would be reduced if everyone was genetically identical depends crucially on how genetically different everyone was in the first place." The review article "The neuroscience of human intelligence differences" by Deary and Johnson and Penke (2010) relates specifically to human intelligence: http://www.larspenke.eu/pdfs/Deary_Penke_Johnson_2010_-_Neuroscience_of_intelligence_review.pdf http://www.larspenke.eu/pdfs/Deary_Penke_Johnson_2010_-_Neur... "At this point, it seems unlikely that single genetic loci have major effects on normal-range intelligence. For example, a modestly sized genome-wide study of the general intelligence factor derived from ten separate test scores in the cAnTAB cognitive test battery did not find any important genome-wide single nucleotide polymorphisms or copy number variants, and did not replicate genetic variants that had previously been associated with cognitive ability[note 48]." The review article Johnson, W. (2010). Understanding the Genetics of Intelligence: Can Height Help? Can Corn Oil?. Current Directions in Psychological Science, 19(3), 177-182 http://apsychoserver.psych.arizona.edu/JJBAReprints/PSYC621/Johnson%20Current%20Directions%20Psych%20Science%202010%20(G%20and%20E%20in%20IQ).pdf http://apsychoserver.psych.arizona.edu/JJBAReprints/PSYC621/... looks at some famous genetic experiments to show how little is explained by gene frequencies even in thoroughly studied populations defined by artificial selection. "Together, however, the developmental natures of GCA and height, the likely influences of gene–environment correlations and interactions on their developmental processes, and the potential for genetic background and environmental circumstances to release previously unexpressed genetic variation suggest that very different combinations of genes may produce identical IQs or heights or levels of any other psychological trait. And the same genes may produce very different IQs and heights against different genetic backgrounds and in different environmental circumstances."

nostrademons 14y ago
"did not find any important genome-wide single nucleotide polymorphisms or copy number variants, and did not replicate genetic variants that had previously been associated with cognitive ability" It's worth making another point here - just because there is no single gene for a trait does not make in unheritable, and just because a trait is genetic does not mean there is a single gene for it. Eye color, for example, is clearly a genetic trait, but may be controlled by as many as 16 different genes. Race is also genetic, but really is shorthand for variation in hundreds, maybe thousands of genes. It's well-established that intelligence is polygenic. That doesn't mean it's not genetic - if everybody had the same genes, ~80% of the variation in intelligence would be eliminated. It also doesn't mean that there's a single genetic switch we can throw to design a master race of human geniuses. It means exactly what it says: that there are some combination of genes that interact together to produce ~70-90% of the variance in the measured quantity that we label "intelligence".
- eevilspock 14y ago
  "Race is also genetic, but really is shorthand for variation in hundreds, maybe thousands of genes." There's a subtlety in your statement that I think will be lost on too many people, even more so given the juxtaposition with the statement about eye color. So at the risk of sounding pedantic... Race is not a trait like eye color. Variations in the human gene pool are not evenly distributed geographically or across ethnic groups for a number of historical reasons. Many of these genes manifest in our physical appearance. But there is no countable number of races. Dividing humanity into 3, 4, 5 or even a hundred races is totally artificial. All you have to do is walk from Europe to SE Asia, or Europe to Africa via the middle east and you will see a gradual change, a gradient for each of the observed physical differences. So description of "race" as a "shorthand" is spot on. Sadly it is a poor shorthand because most everyone conceive of race as discrete types of humans. Sigh.
  - nostrademons 14y ago
    If you have a broad enough cultural background, eye color is not a simple discrete trait either. I was eavesdropping on the conversation behind me on the bus today: "What color would you describe your eyes as?" a guy asks. "Green-ish. Something like that," a girl answers. "Good, you didn't say hazel. A bunch of people would've called them that." And then followed a whole long discussion about how you can basically perform hierarchical agglomerative clustering on humanity's words for colors, if you follow the words linguistically back through a few thousand years. Apparently the first split happened between light & dark, and then broad colors like "blue/green" (as a single color) split off, and then modern languages broke blue & green into separate colors. Some folks break them down even further, into "cerulean" and "turquoise" and "aquamarine" and "royal blue". I've heard (from sources other than the bus conversation) that women actually have significantly more color words in their vocabulary than men do; they make distinctions where men don't. So eye color is a shorthand too. Some people just say "light" or "dark". Others say "brown" or "blue". Still others will break it down into "black", "brown", "blue", "green", and "hazel". Once in a while you'll get a poetic type who'll say "Eyes the color of a roiling sea, as you catch the last glimpse of sunlight before a storm rolls in." Bringing it back on topic, intelligence is a shorthand as well. It stands for a bunch of directly observable characteristics, but which characteristics vary depending on who you ask. Some people think an intelligent person is one with a high IQ who always does well on standardized tests. Others think it's someone who accomplishes great things in the intellectual realm, another Tesla or Einstein. Still others define it as a talent, and claim there're multiple intelligences, each in one desirable realm. Perhaps the meta-lesson isn't about race or eye color or heritability at all, it's to drill down and ask what we actually mean by such broad characteristics. When you make a statement such as "IQ has a heritability of 0.8", you're making a very specific statistical assertion (though even that's not ironclad: which IQ test?). But whether that lines up with the statement of "Intelligence is largely genetic" depends on what you mean by "intelligence" and "genetic", both of which are very broad concepts that hide a lot of subtlety.

marquis 14y ago

Am I the only one who refuses to take an IQ test? I hate being tested - especially with a time limit, I rarely play games (chess and logic puzzles being the exception) but above all I don't understand how anyone could not have an emotional response being told 'your IQ is x'.

sp332 14y ago
Did you have an emotional response when you learned that you could only hold "7, plus or minus 2" things in your short-term working memory? Or when you found out what your adult height was going to be for the rest of your life?
- marquis 14y ago
  >Did you have an emotional response when you learned that you could only hold "7, plus or minus 2" things in your short-term working memory? Well, no - because I could use tools to extend that. And it's not about insecurity, as I'm quite comfortable with myself and my brain. I just don't see it as being a valuable reference. However, I know if I had a number I'd start comparison-shopping and I might feel either elated (if high) or depressed (if low). Is anyone here, if you have had an IQ test, honestly prepared to say that you didn't or wouldn't be curious about what that meant and that it wouldn't affect how you viewed yourself? I just don't need to know. I guess that for me, as long as there isn't a 'goal' or a 'fence', the sky's the limit.
  - mikeash 14y ago
    You can extend your effective IQ using tools as well. I bet your IQ as tested while you have access to an internet-connected computer would be way higher than your IQ as tested on a closed-book test.
    - esrauch 14y ago
      I doubt it, unless you could find a cheat sheet for the test you are taking. It's not like the test is asking about information, facts or calculations; what would you type in to Google to answer a question like this? http://upload.wikimedia.org/wikipedia/commons/thumb/0/0f/RavenMatrix.svg/220px-RavenMatrix.svg.png http://upload.wikimedia.org/wikipedia/commons/thumb/0/0f/Rav...

kevinpet 14y ago

I have no idea what is the author of the articles opinion, and what is from the book being reviewed. I'm not even sure what the title of the book being reviewed is.

agscala 14y ago
I'm glad I wasn't the only one completely confused. I have no idea what he was trying to say, I can't imagine what his book is like.

ilaksh 14y ago

So the vast majority of people misunderstand intelligence, at least as measured by IQ tests, as being a limiting factor for performance and potential, while it is actually just a measurement of current abilities. > the penultimate chapter is a list of 14 examples in which science has failed because of social blindness. This carries through more broadly and generally to the application of many incorrect fundamental assumptions to the design of our institutions, which consistently fail because of the resulting flawed structures.

bearmf 14y ago
It is a limiting factor for many tasks, even such "simple" tasks as basic algebra and calculus. A lot of people fail at math simply because they do not have enough brainpower.
- DiabloD3 14y ago
  No, they fail at math because they have never learned how to use their brainpower effectively. The difference between geniuses and everyone else, from my experiences, are not any fundamental difference in their brain wiring, but that they learned how to better focus what brainpower they do have, Its like the difference between a guy who gives 120% every day but his work, taken individually, is mediocre vs a guy who gives his 1% but his 1% is the Nobel prize winning work of his field... the guy who gives his 120% day in and day out is a smarter man. Ironically, an IQ test will not say much about either of them. The 120% guy might score lower than the 1% man by 10 or 15 points, but the 120% guy, if he were, say, a researcher or inventor, would be spending day in and day out finding thousands of ways that don't work just so he can find one that does. The 120% man learned how to focus the skills he does have and learned how to apply them well; of the two, I'd hire him over the 1% man, Nobel or not. The few super geniuses that history remembers (such as Tesla) had both: 120% work ethic combined with a brilliant mind. These people are rare, but every single person no matter their racial or religious background has the ability to become that kind of person to.... they just never learn how to.
  - victorhn 14y ago

Claudus 14y ago

The Flynn effect tends to be used to support the feeling that intelligence isn't something you're born with. People who think that intelligence is innate will refer to the "g factor". http://en.wikipedia.org/wiki/G_factor_%28psychometrics%29 http://en.wikipedia.org/wiki/G_factor_%28psychometrics%29 The racist (technically speaking) and controversial Jean Rushton believes that "gains in IQ over time (the Lynn-Flynn effect) are unrelated to g". What's really going on with discussions like this is that humanity seems to have come to the conclusion that "smarter is better". Intelligence almost certainly exists, but is quite difficult to quantify exactly, and is further complicated by the fact that people resent others who are "better" than them. Given that there is a genetic component to intelligence to a certain degree, race becomes a factor and leads to a line of inductive reasoning that makes people uncomfortable: 1) Smarter is better 2) Intelligence is genetic 3) Race determines genetics 4) One race is better than another 5) Hitler was right (or other outrageous conclusion) As far as I can tell when you see terms like "g factor", "Flynn effect", "multiple intelligences", "crystallized intelligence", "fluid intelligence", "cultural fair IQ tests", "The bell curve"... people are really secretly arguing about one race or sex being smarter than the other, or not.

bearmf 14y ago
Points 1-2 are valid, though intelligence is not entirely genetic. Your points 3-5 are completely wrong. Genetics determines race, not the other way around. Points 4 and 5 are just meaningless "racist" phrases, not statements in a line of reasoning.
- ajross 14y ago
  It may be semantics, but genetics certainly does not determine "race" alone. If it did, "african american" and "hispanic" wouldn't exist as "races". The idea of classifying people like that doesn't work genetically. First, people have been interbreeding like rabbits throughout history; there are no "pure" stocks anywhere. And more importantly, the amount of genetic variation between any two individuals from the same "race" is much higher than it is, statistically, between the aggregate genetic profiles of distinct "races". Basically, "race" is a cultural distinction. It's a label we apply as a proxy for other stuff (usually cultural). Scientists (well, except anthropologists studying that cultural stuff) don't use it, and for good reason.

bearmf 14y ago

And still IQ is very good at predicting various life outcomes: probabliity of being arrested, income, number of children. Group differences in IQ do exist, and Flynn effect does not make them go away. Flynn effect increases scores across the board, it does not equalize different groups. Black people in US have lower average IQ than white people do, Asian people have higher average IQ. The reasons for this are many, but genetics certainly comes into play: IQ is heritable. Trying to explain away group differences by "culture" is mostly bad science - trying to make the facts fir your desired conclusions.

paranoiacblack 14y ago
No, I agree with this. There was obviously nothing wrong eugenics movement 100 years ago. And obviously minorities get arrested more, have lower income, and a lot of children because of their extremely low IQ as opposed other social forces. See the difference is you are talking out of your ass, whereas Flynn has a book filled with verifiable statistics.
jeremyjh 14y ago
And yet its clear you did not read the article.
Steko 14y ago
Key takeaway from the article: Flynn’s interpretation overturns one of the most dangerous myths of IQ research — that blacks have been shown to be fundamentally less intelligent than whites. With what seems to me to be a series of cast-iron statistical analyses, he shows that this has, in fact, never been proved ... What the evidence actually shows is that racial differences, once all external factors are removed (primarily the social and cultural context of the testees), seem to be almost undetectably small.
- esrauch 14y ago
  I personally don't believe there to be real genetic differences in this context, but that conclusion doesn't seem to preclude there being differences in social and cultural predispositions for different races, then there would still be a direct causal relationship between race and intelligence.

Dylan16807 14y ago

These people aren’t any less intelligent than the researcher — their minds just work differently. They focus on the practicalities they know rather than hypothetical possibilities. That's going to need some explanation. First off, I can see how the question itself is abstract, about a place they have never been, but "no camels" sounds extremely concrete to me. Second, how is ignoring information anything other than a lapse in intelligent thought?

paranoiacblack 14y ago
You're missing the point. If you ask someone a question that expects them to think in a way foreign to them, it does not say anything about their intelligence if they have difficulty approaching it. Think of the old "analytical" thinking questions companies used to give out like "how many golf balls can you fit in a bus", "how many high schools are there in America", etc. Now, I'm not the smartest person but my peers and bosses consider me to be highly intelligent. When I first heard these questions, I was completely stumped. I mean, I've never really taken public transportation and I don't know really have a good idea of how many students go to a typical high school or even how large America is, so how was I supposed to know? However, the population cutoffs for high schools and the size of buses and golf balls are very concrete and well known. Does this show a lapse in my intelligence?
- Dylan16807 14y ago
  The examples you gave only have issues in not knowing the sizes of things. They have nothing to do with thinking in 'foreign ways'. If I show someone a golf ball and ask how many fit into a wagon I expect them to at least say "a lot". If they have math skills then I expect an order-of-magnitude estimate. If you don't know the sizes, then the test-maker has failed you. If you know the sizes and still can't answer, then yes it is a lapse in intelligence. Can you give me an example of a problematic question that isn't caused by using unfamiliar nouns?
  - majormajor 14y ago
    This isn't exactly the same thing as "no camels" but it feels like it's in a similar completely-out-of-your-frame-of-reference ballpark: People thought all-touchscreen devices with no keypad would be useless as phones—they didn't see how the inconvenience of punching numbers in on a touch screen without tactile feedback could be greatly outweighed by other stuff the large touchscreens would end up enabling. Yet it would be ridiculous to say the reason anyone failed to initially grasp the possibilities was a lack of intelligence. I imagine that being told "there are no camels in Germany; how many camels are in this German city?" simply sounded ridiculous to the rural Russians. And so I assume that with no background in abstract reasoning or "word problems" where you're supposed to rely on just the information presented in the problem, they fell back on what they knew about cities: they're places with camels. Imagine if someone came to you from another country and said something like "we don't have people in our cities. But Atlantis is our biggest city. So how many people do you think live there?" It would sound meaningless.

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corporalagumbo 14y ago
Christopher Langan.
hebz0rl 14y ago
http://en.wikipedia.org/wiki/Christopher_Langan http://en.wikipedia.org/wiki/Christopher_Langan
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Alex3917 14y ago

"contrary to widespread assumptions, no clear link between nutrition and IQ has been found." Someone call up Paul Krugman and tell him that iodine deficiency doesn't actually cause mental retardation.

pixelcort 14y ago

OT: Just me, or does browser zoom not seem to increase font size for this page in Safari and Chrome?

peregrine 14y ago
Super annoying, I had to read it in Instapaper just to cope.

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aaron695 14y ago

To not know the answer to "there are no camels in Germany so how many camels do they think there are in B, a specific German city? " is not a cultural difference, to think that other cultures are seriously that dumb is more a statement on ones self than anything else. This is similar to statements engineers sometimes make that the Chinese are good copiers but can't innovate. No, cultures are the same as everyone else. They have humour, art and like to tinker and have in jokes. If they don't publicly innovate it's more likely it's not economical in that environment yet. The fact 'camels' was used has strong undertones to me, if this was an actually a study I'd be interested to know.

eru 14y ago
> No, cultures are the same as everyone else. They have humour, art and like to tinker and have in jokes. Oh, cultures share lots of features. But I've been in a few. Even countries as geographically close as Britain and Germany have quite a few differences.

Aloisius 14y ago

Wait, people take IQ tests seriously? Really? I was tested twice when I was in second grade, the first time by a psychologist in a class setting and the second time one-on-one to verify the first. I tested quite high, but even then I knew I wasn't noticeably smarter than others; I just test particularly well. Frankly, it cracks me up when someone refers to their IQ seriously or boasts about being in Mensa. Other than testing for mid-to-high level mental retardation, subjectively, IQ tests seem to be terrible at measuring actual brilliance.

ghshephard 14y ago
I don't know about "IQ tests seem to be terrible at measuring actual brilliance." - Some of the components of IQ tests are fantastically accurate. I can't read maps, I can't put a monitor back in it's box. And I score very poorly on the pattern assessment components of IQ tests. I guess you might say I'm "mid-to-high level mentally retarded on pattern assessment." Likewise, I have a friend who is world class _stellar_ at putting Monitors back in complicated styrofoam packing and into boxes (Seriously - his ability in this task is amazing) - and he tests off the chart on the pattern recognition component of IQ tests. So - I can, based on the admittedly small anecdotal sample of n=2, suggest that there is strong predictive power of at least some elements of the IQ tests.
- aik 14y ago
  I think the main point is that IQ measures some sort of current fluid intelligence. It doesn't measure other types of intelligence, and most importantly it doesn't measure potential. So the blanket concept of it defining someone's common-understanding-of-"intelligence" is flawed to the extent of it being a pointless or harmful measure in many of cases.
  - ghshephard 14y ago
    What I'm arguing is the opposite - that the IQ test actually is precisely a measure of potential in various abstract areas. Whether you do anything with that potential, or how you develop it (as, in the case of my friend, who is a savant in putting Monitors back into styrofoam boxes) - is a function of resources, opportunity, and interest. Flynn goes further, and suggests that the society and culture that you grow up in, also enhance your ability to execute on IQ tests. The genetic potential (obviously?) hasn't changed, but the environment has shifted such that our "actuated" IQ has increased as we practice more often in abstract tests.

pud 14y ago

Unrelated to the content, when I use Command-plus to increase the font size on this blog (in Chrome, at least), the font doesn't grow. Which means I can't read it, because my eyes suck.

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pmb 14y ago

Two wonderful companions to this article are "Thinking Intelligence is Innate Makes You Stupid" http://lemire.me/blog/archives/2007/12/03/thinking-intelligence-is-innate-makes-you-stupid/ http://lemire.me/blog/archives/2007/12/03/thinking-intellige... and (especially) Cosma Shalizi's article on the malleability and heritability of IQ http://cscs.umich.edu/~crshalizi/weblog/520.html http://cscs.umich.edu/~crshalizi/weblog/520.html

mistercow 14y ago

>For this to happen, evolution would have had to have accelerated to light speed. What? No... no. There are plenty of ways that intelligence could have dramatically increased since the '30s without any evolutionary effects.

avatarlite 14y ago

Anyone interested in this topic should read the primary research papers. The pattern of differences in IQ test answers between generations is not congruent with the pattern of differences between individual who do better and worse on average within generations -- at least according to the few studies which have looked at this question. For this reason, we can infer that the generational changes in IQ test scores are not changes in the same underlying factor that causes differences in performance within a generation. If we call the factor that causes within-generation differences in IQ test scores intelligence, then what differs between generations isn't intelligence. In other words, the Flynn effect is something other than what it might appear at first glance. It's still something of a mystery. Multi-group confirmatory factor analysis can be used to demonstrate this, or you can just look at the correlation matrices.