Born That Way

by William Wright

  A student of Hirsch, Tim Tully, who now researches learning and memory in fruit flies at Cold Spring Harbor Laboratories, is a forceful exponent of Hirsch’s views. Tully dismisses twin and adoption studies for two seemingly contradictory reasons. Like Hirsch, he feels human environments are too variable and their effects too difficult to measure. Environmental elements like diet, climate, and so on cannot be controlled, as they can be with fruit flies. On the other hand, Tully feels the human samples are not broad enough; there is not enough variation in the environments of the people studied, who are mostly white, middle-class Americans—no African bushmen or Peruvian Indians, and, most politically relevant, no black Americans from the inner cities.

  To demonstrate the environment’s power over genes, Tully cites a 1907 experiment by Stockard in which magnesium salts were added to sea water in increasing amounts until two-eyed minnows gave birth to one-eyed offspring. “The idea of one nose, two eyes is as genetically determined as anything,” Tully said to me when I visited his Cold Spring office. “What could be more ubiquitous than two-eyedness? But Stockard showed that if you raise the magnesium level in sea water, the fish embryo would develop one cyclopean eye … It didn’t survive. But there you go, the genetic assumption of two-eyedness disappeared when you change the environment.”

  While Tully was clearly citing the ninety-year-old experiment to demonstrate how susceptible to environmental influence the most rigid genetic instructions are, I later thought it could be seen as proving the opposite. When you consider how many two-eyed creatures there are in the world and, within a species such as Homo sapiens, with populations thriving in environments that range from Amazonian jungles to Siberian ice fields, and when you consider how many of them emerge with two eyes—rarely one eye and never three—it speaks more to the determination of genes to express themselves in spite of environmental fluctuations.

  The world abounds with examples of the awesome power of genes to do their thing in spite of impossible conditions. Outside my office in Key West, where I am writing this chapter, is a brick barbecue pit installed by the previous owners. In the chimney, some five feet above the earth, an oyster plant has sprouted, finding enough nutrients in the cracked grouting to send forth its full complement of well-formed purple and green leaves. It sits there happily, a living chimney corsage, testimony to the oyster plant genome’s determination to express itself, making do with masonry when no soil is available.

  Of course this tropical plant would not thrive at the Arctic Circle or on the roof of a subway car. Any number of environments would defeat its urge to become. But to hypothesize such far-out conditions to prove gene malleability is self-defeating. That Tully and the other environment boosters must resort to extremes like magnesium-laced water to demonstrate the alterability of gene expression does no damage at all to the “normal range of environment” concept. It is a bit like saying that if you squash a bug under your heel, you are affecting the bug’s genetic expression and proving that genes are readily altered.

  (I found it interesting that even Tully, who confined his attack to the science involved, could not resist a swipe at their characters. After listing what he considered behavioral genetics fallacy after fallacy, he said, “You get to the point where you must ask, how many ad rems equal an ad hominem?”)

  The evidence is strong that whether it is magnesium-loaded fish or thalidomide human babies, it takes a lot to throw the gene locomotive off its track. Even the experiments with rhesus monkeys mentioned in chapter 9 in which repeated stressful experiences appeared to permanently alter the monkeys’ neurochemistry, many would argue that this experiment places those monkeys outside of the normal range of environments.

  With a firm grasp of the normal-range concept and an appreciation of the partial nature of genetic influence on behavior, the conclusion seems to be that, yes, genes are powerful in expressing themselves in developed organisms; no, they do not necessarily have great power over the organism’s behavior. These are two distinct levels of potency. One is the level of power to express whatever the genome dictates concerning a behavior, which might be a weak or strong influence. The other is the level of power of those genetic expressions to affect that behavior. The two influences are quite different, yet, sadly, confusingly for the overall argument, they are often taken as the same.

  An analogy frequently used by the environmentalists concerns corn seed raised in rich, fertile soil as opposed to the same seeds grown in dry, nutrient-poor soil. The first will grow straight and full, while the latter will be spindly and twisted. I could not see that such experiments, whether corn or minnows, did more than define the limits of that species’ normal environmental range. No one argues that the environment cannot affect genetic expression. The question is, at what point?

  Sandra Scarr and Thomas Bouchard are among growing numbers of psychologists who believe that, with humans, significant environmental alteration of genetic expression is relatively rare. Hirsch, Tully, Richard Lewontin, and Ruth Hubbard feel it goes on constantly. “We are not just read-outs of our genetic instructions,” Hubbard wrote with exasperation in a letter to The New Yorker. Behavioral geneticists would answer that to a larger degree than ever before suspected, we are. They would also add that the environment—which accounts for roughly 50 percent of behavioral variation—is not just such well-known factors as rearing and education, but less malleable ones such as womb conditions and hormonal surges. To the degree genes do mold behavior and personality traits, their expression still allows for a wide range of performance and behavioral variation. Best of all for the genephobes, this variation would include a capability of totally overruling the ongoing genetic pulls and nudges.

  In response to the critics’ lament that the intricacies of gene-environment interaction invalidate efforts to sort them out, Minnesota’s Matthew McGue responds, “That’s tantamount to saying ‘Let’s not study human behavior. It’s too complex.’ ” Jerry Hirsch, in effect, does say that. In a bow to this position, Bouchard admits that his studies have not challenged the breadth of possible interactions, in that his twins’ environmental range is relatively narrow. “Our results are contingent on a reasonable range of environments and opportunities,” he said. “It doesn’t mean environment is irrelevant.” But on other occasions he echoes McGue’s exasperation with the Tully-Hirsch argument that human environments cannot be controlled, as can those of laboratory animals. “We can’t control the weather or the stars,” he said, “but people study them.”

  Anthropologist Robin Fox, who is now a professor of social theory at Rutgers, in his 1994 book The Challenge of Anthropology shows none of Bouchard’s restraint in responding to the perpetual critical heckling. He dubs the opponents of the biological perspective “leftover, anti-system, left-liberal, chic-radical campus rebels and lumpen Marxists of the 1960s and 1970s … who have lazy minds.” The final zinger refers to Fox’s accusation that the critics have given up on the arduous task of understanding human nature and are content to mouth formulaic opinions instead.

  The codiscoverer of the double helix, James Watson, has a more succinct summation of the Cambridge radical environmentalists. After reading a New York Times op-ed piece by one of them warning against drawing any conclusions from a major study that showed a genetic link with a common behavioral form, a piece Watson found distorted to the point of dishonesty, he snapped, “They’re crooks!”

  THE AUTHORS OF Not in Your Genes are not the only ones to saddle behavioral geneticists with claims they do not make or to use language that subtly misrepresents their work. I was to discover that it goes on constantly. In Myths of Gender by prominent feminist Ann Fausto-Sterling, she speaks scornfully about the “enormous appeal” of the view that “genes dictate our behavior.” Aside from the highly arguable assertion of the appeal of a genetic view with all its frightening intimations of immutability, virtually no behavioral geneticist believes that genes “dictate” behavior. With a similar raising of the other player’s ante by alter
ing the words used, Ruth Hubbard, in her 1993 book Exploding the Gene Myth (written in collaboration with her son, Elijah Wald) complains, “The myth of the all-powerful gene is based on flawed science that discounts the environmental context in which we and our genes exist.”

  Anyone wishing to join Hubbard in the flaw-hurling sport could point to two flaws in Hubbard’s sentence. “The myth of the all-powerful gene” is in itself a myth and can be found nowhere in the behavioral genetics literature. Neither would Hubbard find it easy to locate a behavioral geneticist who “discounts” the environment. Perhaps her misstatement of her opponents’ position stems from the decades when Hubbard’s team were on top and they routinely “discounted” genes and insisted on an “all-powerful environment.” Now that the other side is in the ascendancy, Hubbard wrongfully attributes to them a similar extremism.

  Word games abound among the critics. In 1976, when the I.Q. debate triggered by Jensen was still raging, Leon Kamin wrote: “The adopted child studies, like the separated-twin studies, seem to me to offer no evidence sufficient to reject the hypothesis of zero heritability of I.Q. scores.” A number of years later I was interviewing him in his office at Northeastern University, where he had moved from Princeton. He is a slight man, bankerish, with an amiability and gentleness that belie the ferocity of his combat against the biological perspective. It was hard to imagine him as the man who had won the shoot-out at the O.K. Corral with Sir Cyril Burt. Finding him open and chatty, I asked if he really believed there was no inherited component to I.Q. Kamin smiled mischievously. “Of course there is a genetic component,” he said, “but our techniques of measuring it are too flawed.”

  Few people aware of the volumes of evidence of I.Q. heritability could read his disdainful, one-sentence dismissal of it all without getting the impression that Kamin’s position was: I.Q. is in no way inherited. Not crooked exactly, but not on the level either.

  Kamin styles himself as the watchdog of behavioral genetics, the moral guardian of scientific probity. But this sort of verbal legerdemain, his omission of the Minnesota Twin Study when he evaluated all twin studies, his repeated use of arguments he knows have been disproven, and his highly slanted analysis of Burt’s research all suggest he is playing a far more active role than merely keeping everyone else honest. While he is indefatigable in combing the behavioral genetics data for flaws, more thorough certainly than his fellow critics, he still has yet to do counterresearch, to set up studies that would disprove the work of Bouchard and others. For most scientists, this is the accepted way to refute and, in the end, the only one that means anything.

  IN THE USE OF LANGUAGE, the radical environmentalists have even more invidious ways to misrepresent and trivialize the achievements of behavioral genetics. The champion in this sport is Richard Lewontin, one of the Not in Your Genes authors, who has repeatedly proved he needs no collaborators in his campaign of distortion. A stand-out example was in a review he wrote of a number of books on female biology for the New York Review of Books. After sneeringly discussing the advances in genetic therapies for various major ailments, he then turns to behavior. “The genetic model of disease leads ineluctably to the disease model of all ills and social deviance. So genetic defects are claimed to lie at the basis of heart disease, schizophrenia, alcoholism, drug dependence, violent behavior, unconventional sex, and shoplifting.”

  Behind the intellectually reassuring word ineluctably Lewontin hides twenty years of behavioral genetics research, of which he is well aware but which he chooses to keep from his readers. Instead we are left to suppose that anyone believing in a genetic component to alcoholism or homosexuality does so having leapt with wild illogicality from a belief that cancer and heart disease are genetic as well. And even these medical conditions are, in Lewontin’s presentation, merely “claimed” to have genetic origins. No mention of studies, no pedigrees, no research, no reams of evidence—merely some overly excited geneticists have claimed these illnesses for their domain. Another relevant fact Lewontin fails to include in this article: He has a better cure for all civilization’s ills and social deviance, a political one. Lewontin’s ongoing performance as a leader of the antigenes crowd comes much closer than any to Watson’s blunt characterization.

  If the critics of behavioral genetics would limit their charges to the science rather than the personalities, and, within the science, if they would argue against what has actually been postulated instead of what they fear lies behind the postulations, or what they know will alarm neutral bystanders, they might have plausible arguments, but by ascribing to their opponents claims no one has made, they are tilting at windmills. In other cases, they cite the opposition’s conclusions without giving the evidence on which those conclusions are based. They seem to believe that by leaving out any basis for such conclusions, others will see the achievements of behavioral genetics as windmills as well.

  Because of this sort of twisting of the opposition’s language, the entire debate is thrown into a kind of Looney Tunes melee when all the behavioral geneticists can do at the accusations is sputter, “Who? Me?” In spite of repeated disavowals and efforts to set the record straight, the distortions and misrepresentations continue unabated and render understandable a cri de coeur Sandra Scarr made to me when I told her about a typically distorting letter to the New York Times by a Harvard genetics critic. “I wish,” said Scarr, “they would shut up and listen to what we are saying.”

  IN SPITE OF THE VIGOROUS, sometimes pernicious efforts of the environmental holdouts, there has been a growing acceptance, both in the academic communities and with the public, of the concept of a genetic influence on behavior. The 1992 centennial conference of the American Psychological Association chose two themes that best represented the past, the present, and the future of psychology. Behavioral genetics was one of the themes chosen and a ten-hour series of symposia was organized to examine genetic research in psychology. With such impressive validation, the mainstream media, understandably shy on the subject that had been so politicized, began running interested, even enthusiastic, reviews of behavioral genetic discoveries. A culmination of sorts was reached in the summer of 1994, when a Time magazine cover said in bold letters (no picture): INFIDELITY: IT MAY BE IN OUR GENES. Six months earlier, Minnesota’s David Lykken remarked to me, “The genetic component to behavior has now been well established. It’s time to move on to other things.”

  Lykken’s statement was premature. The June 1993 issue of Scientific American contained an article that purported to be an overview of behavioral genetics but was in actuality an inflammatory and deliberate misrepresentation of the field, with the clear intention of a wholesale debunking. The article’s title and its cover line set the bias level. It was called “Trends in Behavioral Genetics: Eugenics Revisited.” The use of the term eugenics, the most dreaded application of genetic theory, introduced the calumnious charge that behavioral genetics, the effort to find the genetic component in behavior, leads inevitably to social policies aimed at controlling reproductive rights. It was like saying chemists are ipso facto advocates of chemical warfare. The subtitle on the cover was: The Dubious Link Between Genes and Behavior. Had the editors specified human behavior, the magazine might have retained some degree of intellectual respectability (slight, since that would imply humans are not animals), but as it stood, the cover line proudly proclaims the editors’ ignorance of two thousand years of breeding behavioral traits into animals.

  In the text itself, written by a nonscientist named John Horgan, things get worse. In dealing with the Minnesota Twin Study, Horgan talks about the “weird” and “bewitching” coincidences and makes no mentions of the forty-odd research papers the study had produced over twelve years, only two of which allude to the “coincidences.” While the scientific impact of the Minnesota Twin Study is based entirely on these papers, not on the coincidences, readers of Horgan’s article are left with the opposite impression, that Bouchard and the others are basing their claims of genetic behavioral i
nfluences on a few odd twin similarities.

  Readers can infer that there is more to it than Horgan admits when he resurrects all of Leon Kamin’s long-since discredited criticisms of twin studies. Although Horgan was provided with the studies that refute the points (as Bouchard stated in a letter to the editors), he totally ignored them. All of the questions Kamin raises—does contact between twins make them more similar, do twins become more similar if, during rearing, their similarities have been stressed, does recruitment through the media attract twins who exaggerate their similarities?—all these points are matters that can be tested empirically. They have been tested and found to have no effect. But Horgan simply repeats the criticisms and leaves them hanging, as if no one had ever before addressed them.

  Horgan states that behavioral genetics findings have not been replicated, even though Bouchard had explicitly told him of replications, most significantly the replication of his I.Q. results by the Swedish twin study. As it happened, the Swedish study used totally different methods to recruit their twins than had Minnesota, thus strengthening the replication of heritability figures and demolishing the Horgan/Kamin chestnut about media recruitment. In spite of having been informed of all this, Horgan writes that twin studies are unreplicated.

  When Horgan turns to the DNA studies, he cites the misfires such as the Amish and Israeli studies on depression and the Blum study on alcoholism but makes no mention of the ten years of extensive observational studies that have established beyond question a genetic basis for some forms of depression and alcoholism. Here again the reader is left with a totally false impression, that the molecular biologists had gone off on a fool’s quest for a left-handed depression gene based on nothing more than a hunch and had failed to find it.