Tuesday, August 9, 2011

Review of Intelligence and How To Get It: Why Schools and Cultures Count by Richard E. Nisbett

The title really does describe this book. Nisbett sets out to disprove what he says is a prevailing view among intelligence researchers that intelligence is mainly the result of genes. Throughout the book he quotes researchers who have argued against any public efforts to raise the intelligence of the population (particularly the poor) since, as they argue, they would be fruitless, wasted efforts. Instead, Nisbett argues, intelligence is the result of a multitude of influences in a developing child's culture and educational environment. He expresses frustration over the limited amount of scientifically rigorous research in the area, but uses what research there is to mount a convincing argument that both parents and society as a whole have the power to make our kids smarter. I half read it as a mother desiring to raise my children to be as smart as possible, and half read it as an educator and citizen, concerned about the state of education (especially for the poor) in America. The book delivered on both ends.

This book is an interesting read for any laymen interested in intelligence in general, since Nisbett spends a good amount of time explaining different types of intelligence, various tests for intelligence, and their many advantages and flaws. He touches on the role of motivation in achievement, beyond sheer intelligence. The author knew that much of his readership, like me, would be interested for personal reasons, and so the entire last chapter is devoted to quickly and clearly outlining a variety of methods and activities that have been shown through scientific research to improve intellectual ability and performance.

Much of what Nisbett concludes and advocates would certainly be controversial in America's current, polarized political climate. A hefty portion of the book is spent explaining how the conditions of poverty result in a clear intellectual disadvantage:

"There is every reason to believe that the IQ and achievement gaps in the United States could be reduced if people of lower SES (socio-economic status) had higher incomes. Low incomes produce many problems, ranging from poorer nutrition and health, to more disruption due to moving from place to place, to lowered expectations for the rewards of education. In a vicious feedback loop, lower income brings lower academic achievement to lower-status American youth, which in turn lowers their value in the labor market, which results in continued lower SES.

"In a word, if we want the poor to be smarter, we need to find way to make them richer."

But Nisbett makes it clear that he is on the side of science, not any political agenda. Again and again he describes the lack of sufficient, rigorous research which includes proper control groups. And in talking about what works and fails in public schools, he laments that while teacher performance has been shown to make a difference (opposed to more degrees and certifications, and even experience beyond the first few years) teachers' unions have been a block to rewarding individual teachers for performance.

Toward the end, Nisbett even lays out a flat, cost-benefit conclusion regarding the benefits of social programs geared toward raising the intelligence and achievement of the poor:

"Even when benefits are calculated strictly to the taxpayer, in terms of education, welfare, and criminal justice charges saved, the costs of the most successful pre-kindergarten programs are repaid in time."

That Nisbett feels the need to lay it all this cold way further drives home the point that intelligence-is-genetic has seeped into the mentality of many, leading to real feelings of animosity toward the poor and resentment toward the programs which serve them.

Anyone sensitive to issues of race and culture will probably be at least slightly uncomfortable reading the chapters on the particular plight of African Americans and on Asian and Jewish advantages. But it is the sort of discomfort we all need to face if we are to confront the issues at hand and move forward in a direction that promotes greater equality and prosperity. Nisbett points out that taboos against discussing race and intelligence (initially in response to those who have argued that intelligence is mainly genetic) is part of what has caused research to stagnate in finding methods and developing programs that really work to remove disadvantages caused by discrimination.

While Nisbett is optimistic in his final conclusion, he doesn't sugarcoat the situation. The lack of sufficient, scientific research (and often the resistance to such research even being done in the first place!) is a serious problem, as is the complexity of the political, cultural, and social forces being dealt with. But the bottom line is clear: we can close the intelligence gaps between rich and poor, between certain minorities and the majority. We simply need the will to find out what works and what doesn't, and then carry out what does.


  1. Nisbett's book is pseudo-scientific. He misrepresents the relevant research. See this review.

  2. jlovborg, to say that Nisbett's book is "pseudo-scientific" is going rather far. There are plenty of books and articles out there written by non-scientists which claim to be scientific, and Nisbett doesn't fall into that category. He has a PhD in Social Psychology from Columbia and has taught at Yale and the U of Michigan, and his book was about topic within his field of expertise. A far cry from ghosthunters, homeopathy, or the power of crystals, which is the sort of stuff I think of when I hear the term "pseudoscience."

    The review you linked to more makes the case that Nisbett is overly-optimistic and overly certain about his conclusions than misrepresenting research. I thank you for linking to it as it does meaningfully add to the conversation. But it hardly refutes Nisbett's general conclusions. Did you read Nisbett's book? His conclusions are hardly very specific. He seems more to just be countering assumptions in mainstream thought that intelligence and achievement is almost entirely attributable to genes. Frequently in his book, Nisbett decries the lack of sufficient research and calls for more research!

    I am slightly annoyed that you linked to a review written for experts, and refrained from putting the criticisms into your own words. Nisbett's book was written for the layman, and that book review was clearly not. Being a layman myself, I had great difficulty translating what I read in that review into terms I can understand given my own limited academic background. Let us not compare apples to oranges.

  3. Nisbett is a social psychologist, so he is not an expert on intelligence or behavioral genetics. He has never published a single article in any refereed journal specializing in psychometrics or behavioral genetics. His book is not within his field of expertise, and it shows.

    Nisbett misrepresents and selectively cites evidence to support his preconceived conclusions. His arguments against genetic influences on intelligence are nothing new, in fact they are regurgitations of academic Marxist critiques of behavioral genetics from the 1970s. Mainstream science has long ago rejected such anti hereditarian views due to multiple lines of evidence converging to show that differences in general intelligence are primarily caused by additive genetic effects. Nisbett's arguments are particularly ridiculous in light of the fact that the results of traditional pedigree analyses of heritability are currently being confirmed using genomic methods.

    If you want to read a layman's book touching on the topics of nature and nurture, I would recommend "Selfish Reasons to Have More Kids: Why Being a Great Parent is Less Work and More Fun Than You Think" by Bryan Caplan. Caplan's thinking is line with mainstream science, unlike Nisbett's.

  4. jlovborg,

    Your criticisms of Nisbett's book go a great deal father and are quite different from the review you linked to. I have no way to evaluate your claims. What do you base them on? What are your credentials? The article in Science Daily you linked to refers to one study which found that "40% to 50% of people's differences in these abilities could be traced to genetic differences." Indeed, Nisbett doesn't deny that genetics play a role in intelligence. He states clearly and several times that he is arguing against the idea that the vast majority of difference, 90% or more in fact, is due to genetic differences. He also clearly makes the point that genetic differences make a bigger difference among people over a certain economic threshhold. Reminds me an article I read just today about child factor workers in 19th century Europe whose growth was seriously stunted from having to work long shifts 6 days a week in a highly stressful environment. These children's average height by age 18 was dramatically lowered to an average of 62 inches. To compare height to intelligence, no one would argue that genes don't play a huge role in determining height. But at the same time, we also know that certain conditions, particularly prolonged harsh conditions during childhood can and do negatively impact height. No diet, no exercises, or anything else in Danny Devito's childhood would have resulted in his becoming as tall as Michael Jordan. However, had Michael Jordan grown up a factor worker in 19th century Europe, he most certainly would not have grown to be nearly as tall as he is. What Nisbett argues about intelligence is pretty much the same: that what we are able to do to boost intelligence once people are over a certain quality of life threshhold is somewhat minor, but under a certain threshhold, the disadvantages can be great.

  5. My criticisms do not go farther that Lee's review, it's just that one can say things more bluntly in a blog comment than in an academic article.

    The 40 and 50 percent figures in the study represent (quoting from the abstract) "lower bounds for the narrow-sense heritability of the traits", not the full extent of heritability.

    Nisbett's discussion of the SES-heritability interaction is a good example of how he spins the evidence to support his case. He makes much of the fact that adoption to middle-class families boosts the IQs of adoptees from low-class backgrounds. It is well known that the IQs of children can be modified by various interventions, of which adoption is the most radical. But it is also well known that the effects of these interventions do not persist to adulthood -- all of the studies Nisbett discusses deal with children. By late teens the effects of shared environment will be very weak if not nonexistent. For example, in the Minnesota Transracial Adoption Study, conducted by Sandra Scarr and colleagues, a sample of biracial (black-white) adoptees to upper-middle class white families had a mean IQ of 105 at age 7, but by age 17 their mean IQ had declined to 92, a drop of 13 points.

    Nisbett also makes much of Eric Turkheimer's study that showed the heritability of IQ to be very low among low-SES children. From his discussion you would not know that other studies have produced very different results. For example, Robert Plomin did a study of 4-year-old British twins and found that the heritability of non-verbal ability was similar across all environments, whereas the heritability of verbal ability was found to be actually higher in low-SES, high-stress environments. (BTW, Plomin's sample is based on all twins born in the UK in particular years and thus reflects the full range of socioeconomic environments -- there are similar twin cohort studies available from other countries, too, all showing high heritabilities, but Nisbett pretends that these sort of samples do not exist because they completely undermine his range-restriction hypothesis.) Nisbett's modus operandi is to take one outlier study and represent it as definitive without any discussion of other studies with quite different results.

    Very bad childhood environments can of course undermine cognitive development, but one must also remember that today's poorest of the poor in the Western world have material living standards not different from those of middle class families of a few generations ago. This puts a limit to how much the environment can explain.

    I don't see why my qualifications would matter. My beef with Nisbett is not his lack of qualifications but the fact that he misrepresents the results of intelligence research and behavioral genetics. I don't see how I can convince you that I am right unless you are willing to do read up on these topics yourself -- you could start with Judith Rich Harris's "The Nurture Assumption." However, I would suggest that whenever you read something about the "nature and nurture" of IQ, remember the following facts, all well established:

    (1) IQ heritability increase linearly with age. It's about 40 percent in childhood, more than 50 percent in adolescence, more than 60 percent in early adulthood, and about 80 percent in later adulthood.

    (2) Various interventions (including adoptions) can substantially influence IQs in childhood and early adolescence, but these effects have turned out to be ephemeral, vanishing by adulthood.

    (3) Whatever people like Nisbett might claim about the modifiability of IQ, the empirical fact is that one's IQ is highly stable across the lifetime.