The Latest On Intelligence

"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."<p>There is a strong cultural bias among much of the research community to go out of their way to deny any genetic factors in intelligence. Perhaps this is well intentioned, but it is absurd.<p>I have come across very few squirrels that have mastered fire, or could be taught calculus, or even addition. I doubt that this is cultural or due to the squirrels upbringing, diet, social status, or how many books the squirrel has available to it, or the quality of it's teachers, or pathogens. Clearly then, it is possible for genetics to completely dominate other factors in determining intelligence. In the animal kingdom at large heredity/genetics account for basically all of the variation in intelligence.<p>The unanswered question is whether there is enough genetic diversity across the human species to cause intelligence to be significantly hereditable. The fear among scientists that try to keep the lid on this question is that the answer might be yes, and worse that such variations will correlate with geographic or national groupings. This would put a very nasty <i>perceived</i> scientific stamp of approval on racism (even though this would be unjustified), and could over time lead to discrimination and 'scientific racism'.<p>Anyway, in the end science will uncover the truth here, and in the meantime it is probably very prudent to not make any potentially inflammatory statements and to be very cautious about any studies that could fuel hate. I just find it absurd that whenever this kind of question comes up people start denying that there is any hereditary component of intelligence, and that IQ is completely meaningless, etc.

This is an interesting result noted from the paper: "Even when improvements in IQ produced by the most effective early childhood interventions fail to persist, there can be very marked effects on academic achievement and life outcomes."<p>As noted by the author, this suggests that IQ only captures a portion of early childhood intervention benefits. And goes counter to those who suggest that early intervention programs serve no purpose if IQ doesn't remain high (IOW, IQ is only a portion of what constitutes success in life).

Kevin Mitchell has a very interesting take on intelligence here: <a href="http://wiringthebrain.blogspot.com/2012/07/genetics-of-stupidity.html" rel="nofollow">http://wiringthebrain.blogspot.com/2012/07/genetics-of-stupi...</a><p>Basically he suggests thinking about the formation of intelligence to be something like trying to run an obstacle course while holding an armful of things and trying to drop as little as possible. Essentially, he is arguing that there is some optimal or standard brain and since any mutation introduced into the brain is more likely to be harmful than beneficial, more intelligent individuals are not those that inherited some specific genes for intelligence but are most likely those who avoided the most damaging non-specific mutations.<p><i>That’s [runaway selection of intelligence boosting genes] all nice, though admittedly speculative, but those mutations are the ones that we would expect to not vary in human populations – they would now be fixed. In particular, there is little reason to expect that there would exist new mutations in such genes, present in some but not all humans, which act to further increase intelligence. </i><p>To test this he suggests using symmetry as a proxy for robustness in the individual. This fits well with the fact that all attempts thus far to find a common genetic basis for intelligence have failed, the correlation between intelligence and immune function, ideas that intelligence was indirectly selected when optimizing for healthy mates and findings that Nootropic like substances tend to have the least effect on already intelligent minds. In the last case, it is interesting to note nootropics should then be viewed not cheating but more leveling of the playing field. Taking this further, genetics are not the only obstacle course - there is still variation in the womb environment and early childhood. The interplay of genes and the stability of process in the growing brain; affected by a lack of stimulation, poor nutrition and a stressful womb environ would likely have more impactful effects on intelligence than pure genetics.

Am I the only one who reads these kinds reports and has that impression that today's psychology and biology is less than 0.1% of the way to provide a useful model for intelligence? The best measurement of intelligence that we have today (IQ tests) seem completely worthless for practical purpose compared to what we actually need to know to build solutions on. IQ tests are still too bad to measure actual "intelligence", as defined by our colloquial meaning and practical real-world potential. (as opposed to the official technical definition) Being able to measure people's intelligence would be extremely useful. IQ test results, not so much.<p>New findings about the impact of genetic vs environmental influences on IQ tests. Is about as useful finding new evidence about genetic vs environmental influences on people's ability to pass a "lick your elbow" test. Why should I care? It sure is interesting, and hey, anything "for science!". But, meh...

"The extent to which genes matter to intelligence varies by social class (genetic inheritance matters more if you're wealthy, less if you're poor)."<p>It's always seemed obvious to me that this ought to be true - that is that environment will matter more if you have greater differences in environment. In the extreme case if you feed kid A and don't feed kid B, then kid A will end up with an infinitely greater IQ than kid B.

This article is very hard to digest because of the writers switching of "intelligence" and "IQ". Intelligence =/= IQ. IQ is a score on a test, and intelligence is a vague set of mental skills and processes to solve problems of varying degrees and subjects. To say that they are equal is like saying that athleticism is equal to the number of pounds you can bench.<p>If the writer is talking about IQ, then these investigations aren't interesting, as IQ is a very small subset of intelligence (the ability to solve those types of problems on a test, which you can easily train for). If the writer is talking about general intelligence, then the writer really shouldn't be mentioning IQ at all, as it is notorious for being confused as actual intelligence.

Daniel Willingham knows a lot about this subject (I took into to cognition with him a couple of years ago). Of course in the linked article he is just paraphrasing other people's work, but he does a lot of similar stuff himself especially on developmental neuroscience in learning and reasoning. It is very interesting to be taught by someone who knows a ton about learning and how to learn from the neurological point of view.

I didn't read the entire paper, but to someone who did, how much of a link is there between genetics and IQ? I know this isn't a popular subject, but if I remember correctly I believe that Ashkenazi Jews constitute 3% of the population yet have won 27% of the Nobel prizes in science.<p>I would think that much like how different types of people from different regions have differing athletic capabilities, there would also be differences in mental facilities as well -- some better at music, some better at math, etc. Thoughts?

I would upvote this twice if I could. I have read the underlying paper<p>Nisbett, R. E., Aronson, J., Blair, C., Dickens, W., Flynn, J., Halpern, D. F., &#38; Turkheimer, E. (2012, January 2). Intelligence: New Findings and Theoretical Developments. American Psychologist, 67, 130-159.<p><a href="http://psychology.msu.edu/pers_hambric3/PSY493%20Spring%202012/Week%206%20-%20Nisbett%20et%20al.%20(2012).pdf" rel="nofollow">http://psychology.msu.edu/pers_hambric3/PSY493%20Spring%2020...</a><p>Daniel Willingham reviews in the submitted post, and the paper is a joint review article on the last decade and a half of research on human intelligence by an all-star group of researchers.<p>After edit: I see other comments are asking about what the research shows about genetic influences on IQ and environmental influences on IQ. Here is some FAQ information on that, originally part of another comment I posed here on HN:<p>The researchers in the Behavior Genetics Association are making increasingly cautious statements about genetic influence on human behavioral traits as more data are amassed. Here are some of the latest statements by some of the leading researchers.<p>Turkheimer, E. (2012). Genome wide association studies of behavior are social science. In K. S. Plaisance &#38; T.A.C. Reydon (Eds.) Philosophy of Behavioral Biology (pp. 43-64). New York, NY: Springer.<p><a href="http://people.virginia.edu/~ent3c/papers2/Turkheimer%20GWAS%20EWAS%20Final.pdf" rel="nofollow">http://people.virginia.edu/~ent3c/papers2/Turkheimer%20GWAS%...</a><p>"If the history of empirical psychology has taught researchers anything, it is that correlations between causally distant variables cannot be counted on to lead to coherent etiological models."<p>Johnson, W., Turkheimer, E., Gottesman, I. I., &#38; Bouchard, T. J. (2009). Beyond heritability: Twin studies in behavioral research. Current Directions in Psychological Science, 18, 217-220. [I am personally acquainted with three of the four co-authors of this paper, one of whom regularly exchanges links with me by email.]<p><a href="http://people.virginia.edu/~ent3c/papers2/Articles%20for%20Online%20CV/Johnson%20(2009).pdf" rel="nofollow">http://people.virginia.edu/~ent3c/papers2/Articles%20for%20O...</a><p>"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)."<p>Turkheimer, E. (2008, Spring). A better way to use twins for developmental research. LIFE Newsletter, 2, 1-5.<p><a href="http://people.virginia.edu/~ent3c/papers2/Articles%20for%20Online%20CV/Turkheimer%20(2008).pdf" rel="nofollow">http://people.virginia.edu/~ent3c/papers2/Articles%20for%20O...</a><p>"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."

Great quote from page 8 of the actual report:<p>"In particular, there is clear evidence that school affects intelligence."

Some people, and the referenced paper, are citing Jaeggi's dual n-back as evidence that interventions can positively affect g(F) (fluid intelligence).<p>I would like to mention that Jaeggi's results, and working memory training in general, have not been replicated.<p>The main issue with Jaeggi's experiment, is that proper controls were not used.<p>For a careful examination, and I would say thorough debunking of Jaeggi's results on dual n-back and g(F) improvement by training working memory, please read:<p>No Evidence of Intelligence Improvement After Working Memory Training: A Randomized, Placebo-Controlled Study. Redick, Thomas S.; Shipstead, Zach; Harrison, Tyler L.; Hicks, Kenny L.; Fried, David E.; Hambrick, David Z.; Kane, Michael J.; Engle, Randall W. Journal of Experimental Psychology: General, Jun 18 , 2012, No Pagination Specified. doi: 10.1037/a0029082

The best investment a parent can make to improve the child's IQ is DHA, omega 3 fatty acid. It is a key ingredient of a brain, and a typical diet is very deficient in DHA.<p><a href="http://www.diseaseproof.com/archives/healthy-pregnancy-does-omega3-supplementation-during-pregnancy-prevent-postpartum-depression-improve-babys-brain-development.html" rel="nofollow">http://www.diseaseproof.com/archives/healthy-pregnancy-does-...</a><p>Additionally, checkout the: <a href="http://www.omega3.org/" rel="nofollow">http://www.omega3.org/</a>

This article should be titled, “The latest findings on IQ” because IQ score and “intelligence” in a general sense are very different things. Plenty has been published on the inherent cultural and gender biases in IQ testing.<p>Statements like “when babies from poor families are adopted into wealthy families, their IQ goes up” are almost devoid of information because the IQ test itself favors the type of “intelligence” valued by the educated, wealthy class.

In my opinion the reason poorer people have less IQ then wealthier people, and also why adopted poor babys into middle class homes have higher IQ's comes down to what they spend their time thinking about. Poorer people spend their time worrying about food, money and basic needs. This occupys alot of their thought. Richer people don't need to worry about the basic needs and spend their time worrying about larger more complicated things.

Nitpicking but this seems like a contradiction: "It is noteworthy, for example, that at a given level of IQ, Chinese have smaller frontal cortexes than Americans (Chee, Zheng, Goh, &#38; Park, 2011), although Chinese brains as a whole may be larger than those of Americans (Rushton, 2010). Even with brain size equated between Chinese and Americans, the frontal cortex is larger in Americans (Chee et al., 2011)."

The title is misleading. This is not about intelligence, this is about IQ, and that's hardly the same thing. IQ has never been a reliable measure for anything, and something you can improve on by training/repeated exposure is certainly not linked to intelligence.

Studies have shown that the first 5 years of a child's life is when the brain develops the most. Proper nutrition and exposure to simple problem solving will significantly increase the chances of the child having a higher IQ.

I thought it would be interesting to note that my karma score seems to be going up and down a lot on this topic in short periods of time. On other topics, it seems to increase slowly. I'm trying to think of what deeper conclusions could be drawn from this that people have what appear to be strong and varying opinions on something that should be rather scientific and objective.

We cannot engage into this kind of discourse until every party agrees on the definition of "intelligence," and whether intelligence is biological.