Customer Reviews

Intelligence and How to Get It: Why Schools and Cultures Count

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This is a wonderfully well-written book that should be read by anyone with an interest in the heritability of intelligence. Both hereditarians and environmentalists will profit from exposure to the book. Richard Nisbett is an environmentalist and makes an eloquent and accessible case for his cause against those whom he calls "strong hereditarians," those who believe that .75 to .85 of the variation in IQ within a population is heritable.By his definition, he is an environmentalist because he believes that .50 or less of the variation in IQ is heritable. Certainly there are "strong hereditarians," such as Arthur Jensen and J. Philippe Rushton, but the "strong hereditarians" he brings up and criticizes most are Charles Murray and Richard Herrnstein, the authors of the Bell Curve. The problem with this is that by his definition they are closer to the environmentalist side than the hereditarian side because they argue that .60 of the population variation in IQ is heritable (as Nisbett acknowledges on page 210). I mention this because one must bear in mind that among the chief adversaries on this issue, they are separated over whether .50 (or less) or .60 of the variation in IQ is heritable. Indeed, it is worth noting that by Nisbett's definition Judith Rich Harris, the author of The Nurture Assumption and No Two Alike, is an environmentalist.

One clear, but all too typical, error the author makes occurs in his discussion of "stereotype threat," the idea that when their race is made salient, blacks perform worse on IQ and achievement tests because they are afraid of confirming a stereotype. Nisbett asserts that when a test is presented as a puzzle, instead of as a test of intelligence, "black and whites do equally well on the test" ( p.95). This has become the typical take on Claude Steele's and Joshua Aronson original research. What has been lost over the years of interpretation and commentary since the research was done in the mid-1990s, however, is that the Stanford black and white sophomores involved in the study (which involved taking a few questions drawn from the GRE)where matched for their SAT scores they got before entering Stanford. Given the mountain of research now done, we know that stereotype threat is real, and it is possible that it accounts for up to 1/5th of the achievement gap on each of the three sections of the SAT (a standard deviation on each of the three tests). Nonetheless, we also know that most of the cause of the difference between blacks and whites on IQ and achievement tests has nothing to do with stereotype threat. Nisbett's error is shockingly common among even great social psychologists and Claude Steele has helped promote this misconception by what seems to be conscience distortion of his actual findings in accounts of his work in popular magazines like The Atlantic.

Finally, I will note that in the second to last chapter of the book, the author describes the means by which individuals can raise their own and their children's IQs. What he says is interesting enough but he fails to discuss the single most important thing that parents can do for their children--get married and stay married. Now, he does discuss the issue earlier in the book (p. 101), but he fails in the second to last chapter to mention the fact, for example, that Chinese- and Japanese-Americans have an out-of-wedlock birth rate a third that of whites (and 1/8th that of blacks) and they are half as likely to divorce (and a third as likely as blacks). Overall, those groups in the US with the lowest out-of-wedlock birth rates and divorce rates (Asians and Jews) have the highest average IQ, and those with the highest such rates, have the lowest average IQ. The same is true of household income. As Nisbett notes, black households earn 67% of white households but this difference is mainly because black households are much more likely to be single-parent households (which overall earn only 42% of married couple households). Similarly, Japanese-, Chinese-, Filipino- and Indian-American households earn 20 to 30 percent more than white households because they are significantly more likely than white households to have two parents. So, regarding African-Americans, as long as fewer than 40% of African-American children are living with their biological fathers, no matter what else is done, there will be no substantial improvement in black average IQ. For example, Nisbett notes that African-American women are now twice as likely to go to college as African-American males, but what he fails to note is that when one compares African-American boys and girls whose biological parents are married, the boys are as likely to go to college as their sisters. The aggregate difference is exclusively a function of what is going on in single-parent households. In such households girls are vastly more likely to go to college than their brothers. (Could this surprise anyone?) As a Cornell researcher discovered a few years ago, 90 percent of students at the 50 most selective colleges and universities in the US come from intact households. We are as Andrew Hacker says, Two Nations, but the two Nations are not black and white, as Hacker says. We are a nation of the fathered and the fatherless. Until we acknowledge and address that fact, school changes and the like will have no real effect on the intellectual and achievement differences among different groups in the US. We must acknowledge and do something about the elephant in the room.

Brad Lowell Stone

I bought this book based one some gushing reviews and hoping it might do some good for my parenting skills. The main thrust of the book is to dissect the question of whether IQ is a useful test, and if so, whether it comes from your genes or your environment. The author piles on a mountain of evidence that while genes matter, the environment matters at least as much. If you are willing to buy that proposition at the start, then you can skip five of the first 6 chapters without serious loss. In fact the Epilogue nicely summarizes all of this information in just a few pages, so you should just read that first. The most interesting section of these chapters analyzes how certain types of analytical intelligence have actually been improving for the general population over the past few decades due to increased levels of schooling and earlier teaching of symbolic reasoning.

Chapter 4 talks about school as an environment and the main actionable comment is don't let your kid have a rookie teacher.

Chapter 7 talks about how poverty conditions greatly hurt IQ and this information will be quite important for people with a policy interest.

One of the main points of Chapters 4 and 7 is that certain computer-based programs are highly effective at improving IQ for a fairly low price.

Chapters 8 and 9 discuss the disproportionate success of Asian-American and Jewish people. Chapter 8 declares that Asians have normal IQ scores, but they work so hard that they effectively add (e.g. 15 points of) IQ and that makes a huge difference. There is a discussion of differences in Asian and American thinking styles that concludes Asians make good engineers and Americans make good scientists.

Chapter 9 says that Ashkenazi Jewish people *might* actually have a small genetic advantage due to brain anatomy but there is not enough evidence to prove that for sure; Nisbett asserts that, like Asian households, Jewish households emphasize hard work on studying, and this is probably an important reason for their relative success.

Far from endorsing any particular culture or race, Nesbitt points out that there were moments in history when many different cultures - Ancient Arabs, Spanish people, English people, Chinese scholars, etc. - became the most prolific in the world at intellectual achievement. This adds fuel to his point that culture matters.

Overall, Nisbett makes a powerful argument that HARD WORK significantly affects intelligence and that culture, family, schooling and other environmental factors greatly affect hard work and thus can determine intelligence. Therefore, he feels we should not give up any group, because enough of intelligence (or at least +/- 15 points of IQ plus a bunch of inangibles like self-discipline and practical intelligence) is determined by our environment that how we treat people will make a substantial difference in their ultimate success.

Chapter 10 finally gets to parenting and what you can do to improve the intelligence of your child, which comes down to: praising their hard work! Plus a bunch of minor suggestions, which you can read for yourself.

If you have read Malcom Gladwell's Outliers recently as I did (also on my Kindle!), the framework here is completely consistent with his idea: working longer and harder than average is essential to being more successful than average.

If you have not read Outiers yet, then go read it as it is a lot more fun than this book. If you have read Outliers but worried that it lacked academic rigor, then this book should interest you greatly. And if you think that people are either born smart or not, then this book will convince you that how you treat kids will still make a big difference to their future success.

Nisbett's latest book serves several purposes. On one level, he is arguing with his fellow IQ researchers that "schools and culture matter" more than the field suspected (e.g. a 1987 survey by Stanley and Rothman found high estimates of individual heritability and plurality support for the view that both genetic differences and environment played a role in American IQ gaps). Nisbett marshals a persuasive case, and while his thesis is forcefully stated he is scrupulous in pointing out contrary arguments and evidence. Occasionally the main text seemed to overstate a point, but in the vast majority of such cases a turn to the notes section or appendices revealed that the complications had been mentioned there (with a few exceptions related to the views of hereditarians on dysgenics and the causes of low IQ in Africa), and the book could serve as a good introduction to the field for laypeople.

Another major element of the book is a call for bringing scientific rigor to education. Rigorous controlled experiments, research that takes our knowledge of IQ into account, genetics-aware studies such as Eric Turkheimer's (which measure environmental effects on phenomena such as substance abuse using twins to control for genetic effects), and clear thinking have the potential to greatly improve the effectiveness and cost-effectiveness of education and improve cognition. Fear of hereditarian views and associations with racism often hinder educational policymakers from taking our scientific knowledge of IQ into account, with negative effects on educational quality, and we may hope that this text will help to diminish that stigma and help to drive further improvements in cognitive ability.

At a higher level, the book is in some ways an ode to the randomized experiment, taking a strong stand against regressions that are helpless to identify causality and easily manipulable by motivated researchers. A reader gets the sense of a smart and honest empirical scientist who is eager to have questions resolved by hard evidence, and ready to change his mind in accord with those experiments, even when he comes to the table with strongly held initial views on a controversial topic of policy importance. This is something we need to see more of in scientific and policy debates and I give this book my strong recommendation. If you enjoy this book, I would suggest a follow-up with James Flynn's "What is Intelligence?" and Arthur Jensen's "The G-factor."

I will discuss the individual chapters below:

Chapter 1 provides a brief introductory account of IQ, and its importance for life outcomes, while mentioning other important traits such as motivation and self-control. It is quite satisfactory and puts IQ in context, without diminishing its role or getting embroiled in terminological disputes over the description of other abilities or discussion of their measurement.

Chapter 2 attempts to place the high heritability of IQ scores among middle class families (as much as 70-80% of variation in IQ can be explained by genetics within that group) into context, noting that adoptive households tend to be relatively good environments for children (confirmed by across-the-board boosts in IQ for adopted children, although these generally fade with time), and this consistently high quality means that variation in genetics plays a greater relative role. He also cites Turkheimer's research finding lower heritability of IQ among famlies with lower socioeconomic status.

Chapter 3 reviews the literature on the IQ-increasing effects of education, drawing on natural experiments of differential phase-in of education, or disruption due to strikes and disturbances. It is undeniable that schooling increases IQ relative to its absence, and these gains can be lasting. A discussion of the Flynn Effect, the secular increase in IQ scores over the last half century and more, follows James Flynn's "What is Intelligence?" and emphasizes that the particular IQ subtest scores that have increased cover skills that modern education and entertainment place much more emphasis on than in the past. One particularly devastating application is to the critique of 'culture-fair' nonverbal tests such as Raven's Progressive Matrices. These tests, which require subjects to identify patterns in abstract shapes, have shown extremely high culturally-driven increases over time, but they are also used extensively by researchers such as Lynn and Vanhanen to estimate developing country IQ levels. This application is typically defended along the lines that the within-country correlations of life outcomes and Raven scores are strong, but such correlations would not be disrupted by an across-the-board change such as the Flynn Effect (and have not been disrupted in rich countries) or its absence, and these tests are clearly 'culture-unfair.'

Chapter 4 covers the state of educational research, and is one of the best parts of the book, although the findings have been discussed elsewhere. Nisbett urges a scientific approach to educational research and policy, relying on randomized experiments, and critiques the ludicrous excesses of schools of education that reject the experimental method. Reviewing the research on funding levels, teacher quality, and class size, he rejects common myths and focuses on evidence. For instance, teacher quality matters quite a lot for student achievement, but it is not strongly related to seniority after the first two years or to Master's degrees, the criteria according to which most union contracts allocate raises. Instead, direct measurements of student improvement are the best predictors of future performance. Federal policy, the D.C. school system under Mayor Fenty and Michelle Rhee, and the Gates Foundation are all moving in this direction, and I hope that the new wave of experimentally-informed educational practices is able to displace ineffective policies and their political support.

Chapter 5 reviews the large differences in parenting between social classes, e.g. the number of words upper middle class parents speak to their children is much greater than the number spoken by lower class parents, and upper class parents are more encouraging of thought by their children. These results are confounded by genetics, which may simultaneously affect parenting style and child behavior, but they are very interesting nonetheless, and the gains of children raised in adoptive households and some parenting interventions suggest that they do have some causal importance. Importantly, such parenting practices do not change instantly when offspring rise into the middle class, which may be important in explaining the poor test performance of the children of first-generation middle class families of all groups.

Chapter 6 addresses the IQ gap between blacks and whites, arguing for a genetic contribution of zero, and must be read in tandem with Appendix 2, which provides more detailed arguments. Nisbett discusses a substantial partial closing of the IQ gap among children over the last 50 years, and corresponding improvements in school achievement. These gains weaken among teenagers and further among adults, but even on their own they represent a major advance, and suggest that efforts like KIPP could go much further.

Nisbett places a particular focus on evidence from European admixture in African-Americans (on average about 20%). For instance, he notes that skin color, facial features, and blood groups show only tiny correlations with IQ. These arguments turn out not to work because of the sample sizes and the genetics of those traits, but a similar analysis with DNA ancestry testing should now be feasible. More persuasively, Nisbett reviews the mixed evidence from studies of adopted children with one or two black parents. Each of the several studies has confounding effects at play, such as lack of parental IQ information, but collectively they leave it in doubt whether biracial children really do show an advantage over children with two black parents, and pose a challenge for hereditarians selectively focusing on the one (of three) major study showing an advantage for biracial children.

Nisbett presents a number of other lines of argument, with one particularly telling point being the fact that that among African-Americans women predominate in the upper IQ echelons, while among whites the pattern is reversed, and I expect that they will indeed shift scientific opinion towards a lower estimate of the importance of genetics. At the least, we should be confident that environmental interventions, provided that they are validated by randomized trials, can further increase black IQ and that fatalism is mistaken.

Chapter 7 discusses IQ-boosting programs such as the Perry Preschool Program, the Milwaukee Project, and the Abecedarian Program. Overall, there are many disappointing results and some gems, but those gems have shown in randomized experiments that they produce benefits that exceed their costs. IQ gains are often temporary, but a gain that lasts for several years after a program enables increased academic achievement and learning during that time (with lasting benefits), and some gains are significantly more long-lived. More importantly, life outcomes such as employment, use of public assistance, and crime can be dramatically affected. The Obama administration has promised to and is likely to roll out extensive programs along these lines, but the key to success will be rigorous and continuous evaluations that are taken into account in expanding some programs and paring back others.

Chapter 8 covers the high achievement of people of Northeast Asian descent (Japanese, Chinese, Korean). Nisbett correctly emphasizes that regardless of whether or not there is a moderate IQ advantage for these populations, their educational achievements are greatly superior to what would be predicted from IQ alone. Increased conscientiousness due to cultural values of duty to family, a belief in the importance of hard work relative to innate ability, and a tradition of education are cited as explanations for the difference in motivation. One point I would raise here is that cultural environment may also have selected for genetic variations affecting personality. Indeed, a polymorphism at the DRD4 locus associated with ADHD and impulsivity is found in very different regional proportions (it is high in countries recently populated by immigrants, for example) has been found to be extremely scarce in China. A unified stable state living very close to Malthusian margins for many centuries does seem potentially conducive to the evolution of increased conscientiousness among subsistence farmers.

Chapter 9 discusses the high IQ and intellectual achievements of Ashkenazi Jews. With respect to the latter, Nisbett rightly notes that there is strong variation in regional intellectual achievement independently of IQ, e.g. the lack of scientific advance from Texans (even limited to non-Hispanic whites). He discusses various accounts of Ashkenazi intelligence, most importantly the evolutionary biology approach of Cochran, Hardy, and Harpending. Those researchers use statistical analysis to argue that the clustering of Ashkenazi diseases that are linked to increased dendrite growth, myelin in the brain, or increased IQ is vanishingly unlikely unless the Ashkenazim were subject to recent selection, likely due to the extended period when the majority were in finance or related occupations and financial success was strongly associated with numbers of surviving children.

Nisbett thinks that this theory is plausible, although its prediction of increased IQ in heterozygotes for the recessive diseases has not yet been tested, but argues correctly that Jewish achievement exceeds what would be predicted from IQ alone. However, selection for success in moneylending and professional occupations would almost certainly select for self-control and low time preference as well as IQ, so evolutionary considerations may explain more of Ashkenazi success than the chapter suggests. Further genetic differences would support cultural differences: if a high fraction of one's relatives and peers are more intelligent and self-disciplined, that will foster a culture of intellectualism and achievement that will multiply the initial difference. Regardless of the exact causes, they should be studied to determine how to duplicate them elsewhere (whether through education or pharmacology/gene therapy).

Chapter 10 concludes the book with discussion of what parents can do to help cultivate their children's intelligence in a handy presentation that pays attention to relevant caveats and limits of our knowledge. A brief epilogue summarize the main claims of the book and pronounces strong hereditarianism overthrown.

I really enjoyed this book, having previously been stimulated by the author's Geography of Thought. So much of the recent writing about intelligence has been marred by the sloppy use of research, especially in the area of the heritability of intelligence. Nisbett has good appendices explaining the relevant stats and also taking to task the somewhat infamous 'Bell Curve' that I still hear talked about by lay people to this field as gospel. I think he respects those he disagrees with such as Steven Pinker and pays them the respect of not misrepresenting them.

Richard Nisbett's inventive cover says it all: DNA (inherited characteristics) as a ladder to build intelligence on and beyond, rather than as a cage to limit intelligence. With this end in mind, the book includes some marvellously balanced accounts of relevant research and is extremely helpful in overturning the more simplistic interpretations. Nisbett is course not arguing that intelligence is not significantly inherited, just that environmental factors are equally important and recently neglected in much research commentary and policy advocacy. And also environmental factors are what we can strongly influence.

Advocates of the high heritability of intelligence are pessimists and the massive increase in intelligence of the last 50 years across most countries studied by Flynn et al. as Nisbett shows puts a major set of counter data in the way of their perspective. Nisbett is also adept at puncturing the racist use of differential IQ scores between white and black population. This differential is falling dramatically just as average scores also increase.

Among the most interesting insights he provides are those into the identical twins reared apart data. He shows that at the nub of so much misinterpretation is neglect of the simple idea that if two variables determine something and one of the variables is kept roughly stable, then all of the variation is caused by one variable. So if data on identical twins reared apart show 80% of the variation in their intelligence is inherited, you do need to know how varied their backgrounds are. And the answer is probably not very varied. Indeed Nisbett goes on to indicate studies that show upper middle class children having perhaps 70% inherited intelligence, because how they are all raised in very driven, standardized ways, and the top schools are all doing similar things. While children in the lowest part of society have very low heritability of IQ because their environments are so massively varied.

Nisbett has some interesting things to say about cross cultural issues in IQ. But I think his most interesting insight, is that so many Americans now believe that maths talent is inherited, whereas many Asian immigrants to America believe it is the result of damned hard work. This is one of those paradoxes that the most conservative of Americans have embraced inherited ability (Bell Curve etc.) as a way to fend off social engineering via education, while the folk who are overwhelming the gifted programs of America, don't believe this and they seem to be right. There is little IQ difference: the Asian kids just work hard at maths!

For those who come to this book with strong preference towards the high heritability of intelligence, I would simply ask that you open mindedly consider the data and read the sources Nisbett quotes. We need your support to get moving on helping make society smarter. Nisbett has plenty of ideas about further research to really test what works: above all by applying experimental method and having randomly selected control groups for any program to test its real efficacy.

As someone with a general science background I thought this book gave a readable overview of the nature v nurture debate on intelligence and made a good case for a large environment component whilst covering the "hereditary" case. Earlier reviews here question whether the hereditary case was fully made. My conclusion is that there is evidence to support an environmental effect on intelligence...and that the relevant camps can fight out the details.

I read this book primarily to find ways to improve the education of my kids. As Nisbett is an "environmentalist' I assume he has given good cover of this....and yet his suggestions are relatively few in number and a mix of the obvious (ask you kids questions, encourage creative problem solving rather than give them the answer) and others where the details are scant (make good use of computer programs for math, science). Bottom-line: I am encouraged that I am not missing something that is clearly known to have a large benefit. I am left wondering about some of the details eg how to assess and compare computer based education programs but I know the areas I would focus on if I wanted to take things further.

PS If anyone has any info re the Venezuelan problem solving training run by Hernnstein, NIckerson et al and if similar work has been done since 1986 it would be great to hear of it. (referred to on p74 of Nisbett)

PPS The notes section is rather poor--often naming a whole book but not the relevant page/section. Neither notes nor references are numbered within the main text which seems v strange unless it was thought to do so would scare off a lay audience

Nisbett's book addresses two audiences with this book, in a manner that is generally fair-minded and hence persausive.

First, he addresses an audience interested in how culture affects "intelligence", versus genetics. He presents evidence for why culture and other environmental influences have larger effects on intelligence than genetic factors. This discussion touches on some very "hot button" issues, such as differences across ethnic groups in achievement.

Second, he addresses an audience interested in how schools can most effectively increase students' "intelligence" or academic achievement. He reviews evidence on the effectiveness of various academic interventions, such as high-quality preschool and child care, academic programs such as Reading Recovery, whole school reforms such as the KIPP program, and class size reduction. Particularly noteworthy and unusual are his discussions of some educational interventions promoted by social psychologists, such as efforts to persuade students that effort can significantly increase intellectual achievement.

The tone is consistently even-handed. Nisbett frequently discusses arguments and evidence against his positions. With respect to Nisbett's discussion of the influence of culture on intelligence, I do not know the scientific literature sufficiently to judge the accuracy of his summary. However, based on my knowledge of the research on early childhood education and education, I believe Nisbett's summary of this research is generally accurate. He provides the reader with a good guide to some interesting findings in the education literature.

Did you read the 1996 book Bell Curve: Intelligence and Class Structure in American Life (A Free Press Paperbacks Book) and did it make you feel uneasy because you did not (want to) agree with its conclusions but did not exactly know how to refute them? Among its conclusions were (loosely formulated)

1) that intelligence is highly important in many areas of life,

2) that differences in intelligence are largely responsible for societal stratification,

3) that differences in intelligence are largely heritable, and

4) that intelligence gaps between (racial) groups are hard to close (if that is possible at all).

If you felt (feel) uneasy about these conclusions read this book by psychologist Dick Nisbett. You will probably like this book because it will provide answers to your questions. Not in a vague way but in a very specific, well reasoned and research based way. Here are some conclusions from the book:

1) There is no fixed value for the heritability of intelligence. If the environment is very favorable to the growth of development of intelligence, the heritability of intelligence is fairly high (maybe up to 70%. If however the environment is highly variable -differing greatly between individual families- then the environment is going play the major role in differences in intelligences between individuals (as is the case with the poor).

2) Aside from the degree to which heritability is important for one group or another in the population, heritable places no limits whatsoever on modifiability -for anybody,

3) Intelligence is developable and schools can make children smarter, for instance by using computer-assisted teaching and certain types of cooperative learning. 3) Genes play no role at all in race differences in IQ, environment differences do.

4) Believing that intelligence is under your control is a great start of developing intelligence,

5) Certain habits and values in cultures can be highly beneficial for learning and developing intelligence,

6) Parents can do a lot to increase the intelligence and academic achievement of children (both biological and didactic factors matter.

This book is great. [...]Let's hope it will inspire many parents, educators, policymakers and scientists. It just might ...

Nisbett believes that interventions of the right kind can make people smarter, and schools can be made much better than they are now. Further, it is possible to reduce the IQ and achievement gap between the white population and other groups.

General intelligence is a combination of reasoning skills and knowledge. Motivation is another important contributor.

Environmentalists today estimate heritability of IQ at 50% or less, while those emphasizing heredity estimate it at 75-85%. The estimates largely begin with studies of identical and fraternal twins raised either together or apart. The impact of birth order causes an underestimate of heredity, think some.

Psychologist Bronfenbrenner showed that when twins reared apart are brought up in highly similar environments, correlations between IQ scores range from .83 to .91, vs. the more typical .74 - thus giving an inflated estimate of heritability. Others (eg. Devlin) contend that twins sharing the same uterine environment adds 20% inappropriately, though their logic is unclear to me. Still others contend that eg. children with slightly elevated curiosity seek out greater opportunities, demonstrating that heritability is overstated. (My opinion, however, is that they are stretching common sense and their conclusion is inappropriate.)

Research has found that most Jews (except those from North African) have higher IQs, as well as Asian children. Nisbett again cites other research to minimize these findings.

Clearly there are unarguable physical differences between races - eg. African-Americans generally perform much better than Caucasians in many sports. The human brain contains 60+ chemicals - each a potential source of difference in IQ, along with possible physical differences (eg. blood vessel size, oxygen content, various component proportions). Thus, it is illogical to contend ipso facto that all races have the same general intelligence. One suspects that Nisbett's work is biased towards that conclusion.

The good news is that Nisbett also suggests some strategies beneficial to all - eg. physical exercise during pregnancy (leads to bigger and healthier babies), challenging all children, and encouraging them to develop self-control (associated with greater learning). Nisbett also points out that paying for teachers to acquire additional degrees and certification is not effective in helping their pupils.

I give this 2 stars. Good points:

Nisbett acknowledges the solid consensus among expert opinion: the existence of intelligence as a meaningful human trait; many of the population group differences in achievement now found internationally; the heritability of IQ within the White population and its relation to social class; the relation between IQ test scores and MRI-brain size relations; and the neurophysiological reaction time correlates of intelligence (measured in milliseconds).

Also, discussions of brain exercises to temporarily improve working memory like n-back are interesting.

Downside - Omissions and distortions

Unfortunately, Nisbett also out to show that hereditary factors are overplayed while relying on unconvincing research. Worse, there is an avoidance of unwelcome evidence.

For instance, he relies on the work of Eric Turkheimer who studied children who were aged 7 and less. This is long before the shared environmental component vanishes.

This type of error is frequent throughout Nisbett's book: he often "proves" that environment matters more to IQ than previously thought by citing studies of young children. It is only when we reach adulthood that the full effect of our hereditary factors occurs, so estimates of the heritability of intelligence ought to be based on adult IQ scores.

Nisbett claims that the "Flynn effect," or secular gains in IQ across the industrialized world, proves that people are becoming more intelligent and that intelligence is substantially more dependent on environment than previously believed. However, the increases have been on certain parts of the tests. For instance, visuo-spatial logic has improved considerably but vocabulary and math have shown little improvement. If there was some general improvement this would show up on all aspects. Also, reaction time measures which correlate strongly with 'g' or the general intelligence factor have not improved. Furthermore, the Flynn effect has not shown that gaps between groups have reduced.

Nisbett claims most estimates of heritability have been based almost exclusively on studies of middle-class groups. What he overlooks is that group differences are larger at the highest level of SES than at the lowest.

He uses as evidence a French Adoption study, but his interpretation of it is pretty questionable. There is an excellent discussion of this on the Gene Expression site - the conclusions:

* The results of the French cross-fostering adoption study strongly support the consensus that heredity accounts for a substantial portion of the variance in mental test scores.

* It is certainly possible that substantial environmental effects can be found where the range of SES is unrestricted. It is unclear, however, that the effects demonstrated here in particular are stable over time. Longitudinal follow-up would have been informative.

* It may be that the genetic effect on mental test scores is concentrated in the g factor. This is important for many reasons, including the general agreement that g accounts for the bulk of the predictive validity of IQ with respect to practical, real-life criteria. More rigorous approaches to this question than my own may be possible.

* These results, while by no means deciding the matter, also leave entirely intact the reasonableness of the hypothesis that genetic differences account for as much of the b-w IQ gap as do environmental factors.

As another poster has noted, the following 40 page review of this book uncovers a surprising number of distortions and instances where Nisbett has overlooked contradictory evidence.

Rushton, J. P., & Jensen, A. R. (2009). A Theory-Based Review of the Research in Richard Nisbett's Intelligence and How to Get It. Working paper, Department of Psychology, University of Western Ontario, London, Canada.

Another review by James J Lee of Harvard comments:

Abstract: Richard Nisbett's intelligence and how to get it advances several interlocking claims: (1) the heritability of IQ is far lower than typically claimed by behavioral geneticists, (2) the IQ differences across social classes are largely environmental in origin, (3) the IQ differences across racial groups are entirely environmental in origin, and (4) these group differences can be narrowed substantially by interventions that social scientists have already discovered. In this review I show that Nisbett's arguments are consistently overstated or unsound..

Personality and Individual Differences Volume 48, Issue 2, January 2010, Pages 247-255

Like almost all other books on the subject, this one tries to make sure

that you understand that the writer does not have an agenda (hidden or not).

And like most other books on the subject the contrary is quite evident.

While Prof. Nisbett gives a clear presentation of a number of interesting

studies that support his views, he does not fully explain the

inherent difficulties in interpreting their results. I believe that doing so would result

in a technical discussion without a clear conclusion or message. But

I also believe that this is where we currently are - and why the particular

debate of nature vs. nurture will go on for generations to come.

Let me be clear - I enjoyed the book, and I do ultimately believe that

many of the conclusions are true. However, not being a specialist in

the area, and without going to the original literature, I am at a

loss about how to evaluate the supporting evidence. For instance,

I can't take seriously anybody claiming that this factor or that is responsible for

.5 SD in IQ. While it has the feel of nicely summarizing the outcome of

one or more studies, I don't think the statement is interpretable.

With this in mind, I would still recommend the book - it tries to address

a very relevant topic. It serves as a good introduction to the questions, and the

difficulties in studying them. However, one should be very cautious in

accepting the proposed answers.