How The Bell Curve Naturalized Inequality

Almost 30 years ago, The Bell Curve claimed to show a causal connection between genetics and inequality. It further discredited the field among many on the Left, but a proper understanding of genetics actually reveals the social causes of inequality.

Charles Murray during a debate with Alvin Poussaint at Carleton College, Minnesota, April 11, 1995. (Rita Reed / Star Tribune via Getty Images)

Almost three decades ago, the psychologist Richard Herrnstein and the political scientist Charles Murray published The Bell Curve: Intelligence and Class Structure in American Life. Its release was a watershed moment in the popular reception of science, in part because it purported to solve, once and for all, the seemingly intractable problem of whether nature or nurture were decisive in determining people’s life outcomes. The Bell Curve provided an explanation of class inequality in the United States that laid the blame of differential social outcomes on genetically entrenched differences between groups.

The political implications of these arguments were not hard to imagine. Already in the 1970s, economic slowdown and the abandonment of the New Deal project had created a context in which politicians were beginning to acclimatize themselves to a world in which redistribution as an aim of politics had been abandoned. Inequality was no longer the fault of an economic system, but the result of what politicians across both aisles described as a “culture of poverty.” Talk of the underclass, a barely civilized subsection of society, became all the rage as politicians looked for ways of blaming ordinary people for their inability to tackle the causes of deindustrialization, unemployment, and poverty.

The Bell Curve merged a culture of poverty argument with hereditarianism, which is the position that the causes of inequality are inborn and unavoidable. A meritocratic system, Herrnstein and Murray argued, metes out rewards of status and wealth based on the inborn talent of individuals. In systems where social mobility is more or less impossible, such as in a feudal society, genetics matters little for the difference between prince and peasant. Liberal capitalist societies, as Herrnstein and Murray argue, allow for social mobility and natural ability to exert a strong influence on the eventual social positions of individuals. As the generations go on, class becomes genetically entrenched and, ultimately, puts hard limits on the possibilities of social mobility. Similar dynamics of ingrained genetic difference were also, the authors argued, responsible for the persistence of racial inequality.

Understandably, these arguments provoked the ire of progressively minded scientists and commentators. However, the sweeping and reflexive manner in which opponents of the hereditarian arguments advanced their objections to The Bell Curve often led these critics to adopt counterproductive conclusions. Unhelpfully, they conflated two distinct issues. The first is the question of what it means to claim that something is genetic, and the second is the inevitability of certain life outcomes based on the biology of a particular organism.

Properly speaking, genetics concerns some characteristic of an organism varying across individuals in a group in a given context. It is, by definition, not an explanation of the behavior or development of a given individual in a given instance. Conflating the issue of the causes of differences with that of the inevitability of the development of a particular organism is an important part of the hereditarian rhetorical strategy deployed by the likes of Herrnstein and Murray. To the extent that their arguments have managed to gain some traction in the world, it has been because they have managed to convince their critics to commit the error for them.

The Confused Physician

The confusion underlying Herrnstein and Murray’s arguments becomes clear when we apply them to another context. Suppose you are visiting the doctor for a checkup and that as part of your pre-checkup routine you are subjected to a genetic screen. Imagine, too, that in the pamphlet given to you by your health care provider, you read that by retrieving the genetic code from many small sections of your genome, medical professionals will be able to identify whether you are at elevated risk for developing certain diseases. For twenty minutes you sit alone on an examination table, awaiting your results, before the doctor walks in through the door of the medical examining room, stands before you and stares at your chart; a short but pregnant silence follows, punctuated, finally, by your doctor saying, “Your genomics results say that you are going to develop bone cancer. You’re screwed.” They then walk out of the examination room and an orderly shepherds you to the checkout desk to be handed a pile of paperwork.

This is not at all how the genome project and the genetic component of the war on cancer has been sold to funding agencies, medical professionals, and the general public. Rather, scientists and medical professionals insisted that a deeper understanding of the genome and its relationship to life outcomes would open a new world of possibilities for intervention to prevent and cure diseases like cancer. Instead of genetic causes being viewed as determinative and inevitable, they are held up as the keys to changing life for the better. While this view still locates the source of the important difference within the individual and takes a narrow pharmaceutical path toward intervention, it still emphasizes change.

Now, contrast this medical view with the hereditarian claims advanced by Herrnstein, Murray, and their acolytes of how evolved genetic influences supposedly structure inequality in society. Under the hereditarian account, individuals from different socially defined racial groups tend to draw their ancestry from different parts of the world. Further, groups in different parts of the world have semi-independent evolutionary histories going back many thousands of generations, which allows considerable time for genetic differences to build up among them.

Hereditarians then point to studies purporting to show that putative psychological characteristics, usually intelligence test scores, are correlated with social and economic success and tend to vary between classes and racial groups. They will then claim that these psychological characteristics are heritable, which means that relatives tend to resemble one another more than they do randomly selected individuals in a manner that is related to their degree of relatedness. The hereditarian then concludes that genetic differences determine social differences and that no intervention will be able to ameliorate these inequalities.

This is not to say that the medical view of the genetic etiology of disease and the narrowly chemical view of possible intervention is not ripe for criticism. While our physician, however, may have a blinkered view of intervention, they nevertheless believe that change is both possible and worth pursuing. For the hereditarian, the same kinds of facts that a doctor treats as the motivation for medical intervention instead justify belief in the inevitability of inequality.

Genetics and Inevitability

But the confusion in Murray and Herrnstein’s thinking doesn’t just stop at their pessimism about the kind of practical responses to differences purportedly caused by genetics — it goes all the way down to their understanding of what genetics is. Let’s start by clarifying what we mean by “genetic” and outline why that which is genetic is not necessarily inevitable. For one, genetics deals with groups of organisms rather than the life outcomes of individual organisms. All organisms have genes, but it takes groups of organisms to have genetics because genetics is ultimately about how variation is structured within a group.

Take a single tomato plant in isolation. It has a genome that is between one-fourth and one-third the size of that of a human’s in terms of the raw amount of DNA. Inside its genome are a few tens of thousands of genes, which, in this case, are stretches of the genome that form a chemical template for the cellular production of the proteins and other biochemicals that are vital for the structure and function of organisms. However, since we are dealing with a single plant at a single point in time, there is no comparative context that would allow us to identify the differences among organisms that characterize the rich diversity of life.

But even having many organisms to compare is not sufficient for a biological system to display genetics in the proper sense of the term. Genetics in the sense that matters is ultimately about variation that arises from genetic differences. To see this, think again about tomatoes. They can be cloned with ease by taking cuttings from a single plant and growing them in their own allotments of soil. Genetically, the different newly individualized plants will be identical to one another, with the exception of a very few mutations — spontaneous changes to DNA that can occur during cellular replication.

If we were to compare a large number of these cloned tomato plants, we would find many differences among them. The shape and sizes of leaves would differ, as would the coloration of the fruits and the pattern of branching along the stalks. Since, on account of being clones, the plants are all genetically identical, these differences could not be attributable to genetics. While each of the plants has genes and we have a group of plants to form the basis for comparison needed to establish that there is variation, there are no genetic differences among the plants that could account for any of that variation. That is, while our tomato plants have genes, they display no genetic differences among one another despite having physiological differences.

For us to find genetic causes of differentiation among tomatoes, we would need to look more closely at the world of tomatoes. To do so, we might choose several genetically differing varietals and undertake a several-generations-long breeding experiment to mix up the genetic material among plants so that each plant produced at the end of the experiment represented a random selection of possible tomato genetic variations. Were we to do this, we would most likely find that variation was patterned in a markedly different way in the cloned and genetically variable group alike. Any pair of closely related clones would no more resemble one another than any randomly selected pair of individuals in the clone group, but close relatives in the genetically variable group would be more alike than we would expect by chance. This is because relatives tend to share genetic variants on account of inheriting them from recent common ancestors.

Note that when we talk about variation among organisms, our statements about how organisms differ are both relative and dependent on a frame of reference. They are relative in that, while we can say something about why tomato plants differ from one another in, say, their height, we are not able to make any sensible statements about why any single tomato plant is exactly as tall as it is without detailed understandings of physiology and growth coupled with the environmental conditions under which the plant is growing. The study of genetics can help us build holistic biological accounts of an organism, but it is not able to do all of the work on its own.

Exposing the rhetorical sleight of hand involving the conflation of “genetic” with “determined” undermines a key component of the hereditarian argument, including the one in Herrnstein and Murray’s The Bell Curve. A given genotype — a combination of genetic variants carried by the organism — may have different effects on phenotype — the physical, behavioral, and physiological properties of an organism — in different natural or social environmental contexts. Without exploring the vast social space in which human beings might develop, learn, thrive, and struggle, no meaningful conclusions can be drawn about the fixity or malleability of human behavior.

Hiding the fact that an understanding of genetics is dependent on an understanding of the world in which organisms, especially human ones, exist is key to the success of Murray and Herrnstein’s arguments. By only focusing on what is observed in a single context, which is itself a product of a history that is by no means inevitable, the hereditarian argument treats the conditions of life and society as we experience them as though there were no alternatives. Hiding behind biological technobabble, hereditarians can than easily make the unwarranted transition between a statement about the effects of genes as reckoned in a single case to a claim of universal genetic determinism.

Avoiding the Genetic Trap

Most perniciously, this unwarranted leap from the contingent facts of the particular to claims about what is universal and inevitable is so ingrained in the broader scholarly and public understanding of genetics that it has even come to be accepted by critics of hereditarianism. Motivated by progressive aims, too many anti-hereditarians take the bait and leap right into the jaws of the genetic trap by attacking genetics itself, as though the many shortcomings of the science promoted by hereditarians and other determinists was the core problem.

Nowhere is this clearer than in the rush of scientists to embrace the nascent field of epigenetics, which, in its most extreme and overhyped form, posits considerable inheritance of acquired characteristics in a nongenetic fashion, resurrecting Lamarckism for the twenty-first century. Many scientists will even go out of their way to avoid genetics because they themselves buy into the falsehood that “genetic” means “determined.” In addition to being an ineffective response to hereditarianism, the frequency with which critics step into the genetic trap gives hereditarianism support by strengthening the often-unstated framing of social problems as being located in the basic constitution of individuals in an inevitable world, as opposed to calling for us to dedicate our efforts toward finding new social organizations to address historically contingent and by no means inevitable inequalities.

A good first step in combating hereditarianism is to stop agreeing with it. The second step is to turn our attention to the social world, examining the causes of poverty and human suffering that are often clear enough to be observed even without the use of a microscope.