summaries of chapters in The Bell Curve (for those who don't want to read the whole thing!)

The purpose of this blog post is to detail the complete, unedited chapter summaries that Charles Murray has posted from his book, The Bell Curve (TBC), co-authored with Richard Hernnstein. Before I get there, I'll do a review of Murray's other works and discuss the controversy over TBC a bit (especially the fascist riots by self-styled liberals at Middlebury).

Murray is most famous for TBC, by far his most controversial book. The hubbub is a shame for a few reasons. First, Murray has done some really important and useful work in a variety of social and political arenas. The controversy over TBC may bring attention to his other work, but probably tends to overshadow it. In Pursuit of Happiness and Good Government is terrific for thinking through our goals and strategies in public policy, whatever one's worldview. If one wants to go from good intentions to good policy, the book is somewhere between really helpful and must-reading. 

Losing Ground was THE book on welfare in the 1980s, driving part of the debate, and laying out the theoretical and empirical case for the damage necessarily done to family structures by welfare policies-- mostly for the poor and those in the lower middle classes. Losing Ground may have been more controversial than TBC when it came out, but soon, it became conventional wisdom! (Here's a review of both books in one blog post.)

More recently, Coming Apart revisited and broadened the argument in Losing Ground, noting that the lower classes are falling apart with respect to family stability and structure, leading to a range of social pathologies in those communities. Meanwhile, the upper-income classes are holding their families together for the most part, leading to the range of advantages that go with family stability and structure. Thus, we end up with two Americas and a society that threatens to "come apart". (For my journal article on this, click here.) Another provocative extension of this work is his effort to research what he calls "the bubble effect".

Second, all that said: if TBC is a huge mess and he has not recanted, then Murray certainly deserves to take a beating. But here's the thing: his analysis and conclusions are, at most, debatable. Far worse, many of his opponents won't engage the arguments and haven't even read the book! In the Spring, Murray was invited to speak at Middlebury College about Coming Apart-- by a liberal professor who disagreed with a lot of what Murray had written. But students shouted Murray down and rioted, attacking Murray and his host. It's impossible to take the moral high ground (even if it can be taken from Murray on the merits of his arguments) when you're using those tactics AND you haven't even read the book! But maybe that's the point: intellectual laziness, the pursuit of power, secular fundamentalism, a reliance on intolerance-- just to get your way. What's more illiberal than that?


Murray revisited TBC in 2005 with this summary article-- and then again, 20 years later with AEI. But I don't think either effort got much notice. In May, a few months after Middlebury, Murray got permission from his publisher to re-publish the chapter summaries in TBC-- a more intentional and impressive effort which I will link, summarize/highlight, and comment upon below. (Murray says that a podcast he did with Sam Harris gave him the idea-- after the podcast received such a hopeful and positive response.) Hopefully, this will get a lot of attention.

I think the real issue is that the topic is somewhat sensitive, somewhat complicated (people get easily confused even by basic statistics), and his policy suggestions run counter to some sacred cows among illiberals on the Left. What else explains the rabid responses of people who won't even read the work (or summaries of it)? Well, yes, it could simply be rank fundamentalism of the nastiest sort! But let's hope this can be overcome. (In a separate post, I'll deal with academics who obviously mis-characterize Murray and TBC prominent academic journals-- as well as a pop piece in Vox.)

If reading the entire book is too much for you, fine. (I haven't read it and don't plan to!) But if you don't want to look like a tool, like to see yourself as a liberal reader and thinker, and even think you could possibly learn something, why not read the Cliffnotes version-- or even, my Cliffnotes of his Cliffnotes-- huh?

Excerpts from the Introduction to the Book

"...for the last thirty years, the concept of intelligence has been a pariah in the world of ideas. The attempt to measure it with tests has been variously dismissed as an artifact of racism, political reaction, statistical bungling, and scholarly fraud. Many of you have reached this page assuming that these accusations are proved. In such a context comes this book, blithely proceeding on the assumption that intelligence is a reasonably well-understood construct, measured with accuracy and fairness by any number of standardized mental tests." 

So, MH provide "six conclusions...from the classical tradition" that they will review and then use to get rolling. (Murray notes that the Neisser et. al. journal article includes "knowns" that correspond to all six of these): 

1. There is such a thing as a general factor of cognitive ability on which human beings differ.
2. All standardized tests of academic aptitude or achievement measure this general factor to some degree, but IQ tests expressly designed for that purpose measure it most accurately.
3. IQ scores match, to a first degree, whatever it is that people mean when they use the word intelligent or smart in ordinary language.
4. IQ scores are stable, although not perfectly so, over much of a person’s life.
5. Properly administered IQ tests are not demonstrably biased against social, economic, ethnic, or racial groups.
6. Cognitive ability is substantially heritable, apparently no less than 40 percent and no more than 80 percent.

From there, Murray and Hernnstein (MH) talk about the crucial differences between drawing inferences about a.) two individuals (with IQ's of 90 and 110); and b.) two small, relatively homogeneous groups of people (two sixth grade classes with average IQ's of 90 and 110). They describe the lack of confidence one should have in drawing inferences in the former case and the significant confidence one would have in the latter. 

In sum, "All of this is another way of making a point so important that we will italicize it now and repeat elsewhere: Measures of intelligence have reliable statistical relationships with important social phenomena, but they are a limited tool for deciding what to make of any given individual. Repeat it we must, for one of the problems of writing about intelligence is how to remind readers often enough how little an IQ score tells about whether the human being next to you is someone whom you will admire or cherish. This thing we know as IQ is important but not a synonym for human excellence." (italics theirs)

MH agree that intelligence is vastly over-rated as a virtue-- and that the term "intelligence" carries "with it undue affect and political baggage", so they prefer "cognitive ability" instead. Likewise, they will use IQ "as a generic synonym for intelligence test score." All of this is to help the reader "think of intelligence as just a noun, not an accolade."

Excerpts from Part 1

Part 1 looks at "the cognitive elite"-- the top. (Part 2 looks at "the bottom" of the spectrum.) MH discuss the rapid increase in college attendance throughout the 20th century, "the democratization of higher education", but also the increase in efficient selection by elite colleges based on IQ. This efficient selection really got rolling in the 1950s with a booming economy (with higher and growing incomes) and plummeting communication and transportation costs (making college far away from home much more viable). Where the brightest used to attend their local schools, they now shipped off to Harvard and other elite schools. From there, students tended to marry-- "assortative mating"-- impacting the genetics and the environment of the resulting marriages and families. 

At the same time, IQ was becoming more important within the economy, as we started to move from a manufacturing-based economy to a services and government-based economy. IQ has always been helpful within professions; people with higher IQs tend to earn more. Now, the growing variety of jobs made IQ even more relevant to earnings and career outcomes.

Excerpts from Part 2

Part 2 focuses on their "best estimate of how much intelligence has to do with America's most pressing social problems". Their short answer is "quite a lot", since cognitive ability is associated with patterns of social behavior. Again, MH reiterate that there's a huge difference between making generalizations about individuals vs. groups. But they argue that "intelligence itself, not just its correlation with socioeconomic status, is responsible for these group differences." 

They restrict their analysis to whites where the data permit it (to try to keep race out of it as a confounding or distracting factor.) In Chapter 5, MH explore the connections to poverty-- with IQ slightly more important than marital status, both of which easily outpace other factors. Chapter 6 is schooling. Chapter 7 is unemployment, idleness and injury. In Chapter 8, they look at correlations between intelligence and illegitimacy. Chapter 9 is welfare dependency. Chapter 10 is parenting. Chapter 11 is crime. Chapter 12 is civility and citizenship. Not a pretty sight.

Excerpts from Part 3

I love the intro to this section: "Part II was circumscribed, taking on social behaviors one at a time, focusing on causal roles, with the analysis restricted to whites wherever the data permitted. We now turn to the national scene. This means considering all races and ethnic groups, which leads to the most controversial issues we will discuss: ethnic differences in cognitive ability and social behavior, the effects of fertility patterns on the distribution of intelligence, and the overall relationship of low cognitive ability to what has become known as the underclass. As we begin, perhaps a pact is appropriate. The facts about these topics are not only controversial but exceedingly complex. For our part, we will undertake to confront all the tough questions squarely. We ask that you read carefully."

Read carefully?! Yeah, good luck with that, Charles! If he'd known how little and how carelessly people would read, would he have had the courage to write?

A summary follows immediately: "Despite the forbidding air that envelops the topic, ethnic differences in cognitive ability are neither surprising nor in doubt. Large human populations differ in many ways, both cultural and biological. It is not surprising that they might differ at least slightly in their cognitive characteristics. That they do is confirmed by the data on ethnic differences in cognitive ability from around the world. One message of this chapter is that such differences are real and have consequences. Another is that the facts are not as alarming as many people seem to fear."

From there, MH details differences in general IQ and particular components of IQ for various racial groups. Their wrap to chapter 13 revisits our inability to talk civilly, to embrace Science, and to do science in this area: "Nothing seems more fearsome to many commentators than the possibility that ethnic and race differences have any genetic component at all. This belief is a fundamental error. Even if the differences between races were entirely genetic (which they surely are not), it should make no practical difference in how individuals deal with each other. The real danger is that the elite wisdom on ethnic differences—that such differences cannot exist—will shift to opposite and equally unjustified extremes. Open and informed discussion is the one certain way to protect society from the dangers of one extreme view or the other."

Chapter 14 provides details on how these differences play out in terms of the outcomes in Part II (chapters 5-12 above). Chapter 15 talks about demographic shifts and the implications for IQ and outcomes. 

Chapter 16 wraps up in this manner: "In this chapter, the question is not whether low cognitive ability causes social problems but the prevalence of low cognitive ability among people who have those problems. It is an important distinction. Causal relationships are complex and hard to establish definitely. The measure of prevalence is more straightforward. For most of the worst social problems of our time, the people who have the problem are heavily concentrated in the lower portion of the cognitive ability distribution. Any practical solution must therefore be capable of succeeding with such people." It's difficult to argue with this, huh?

Excerpts from Part 4

Again, the summary to open Part 4 is quite helpful: "Our analysis provides few clear and decisive solutions to the major domestic issues of the day. But, at the same time, there is no major domestic issue for which the news we bring is irrelevant."

Examples? "Do we want to persuade poor single teenagers not to have babies? The knowledge that 95 percent of poor teenage women who have babies are also below average in intelligence should prompt skepticism about strategies that rely on abstract and far-sighted calculations of self-interest. Do we favor job training programs for chronically unemployed men? Any program is going to fail unless it is designed for a target population half of which has IQs below 80. Do we wish to reduce income inequality? If so, we need to understand how the market for cognitive ability drives the process. Do we aspire to a 'world class' educational system for America? Before deciding what is wrong with the current system, we had better think hard about how cognitive ability and education are linked. Part IV tries to lay out some of these connections."  

In this, you can see Murray's thinking a la In Pursuit of Happiness and Good Government: whatever you're trying to do with government policy, clear thinking about reality is a prerequisite to having any confidence in your project. Is there any debate there?

Chapter 17 talks about potential ways to increase IQ, but doing so "is not easy". Nutrition may be the best opportunity, esp. in less-developed countries. Formal schooling and preschool don't seem to work well. Adoption at birth is responsible for an increase of six points-- "not spectacular but not negligible either". Chapter 18 focuses harder on options within education-- in particular, providing choice and competition to enhance educational quality. So, right here, we can see why statists, those who lack policy imagination, and crony capitalists will start to foam at the mouth and look for reasons to hate the book. Chapters 19 and 20 talk about the pros and cons of Affirmative Action in education and the workplace-- two more sacred cows. 

Chapter 21 talks about the trends, something that Murray continues to update and explore in Coming Apart. Chapter 22 encourages policy makers to pursue targeted vs. blanket policy solutions-- and to address cognitive ability as relevant (instead of ignoring it).

And then, to wrap things up, check out their final recommendation: "Group differences in cognitive ability, so desperately denied for so long, can best be handled—can only be handled—by a return to individualism. A person should not be judged as a member of a group but as an individual. With that cornerstone of the American doctrine once again in place, group differences can take their appropriately insignificant place in affecting American life. But until that cornerstone is once again in place, the anger, the hurt, and the animosities will continue to grow."  

What irony that MH are the ones who want to look at people as individuals, while their opponents are obsessed with seeing people mostly as members of various politically-defined identity groups. What a strange world we inhabit!