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International Socialist Review Issue 41, May–June 2005

Genes, Evolution and Human Nature


Phil Gasper is a member of the ISR editorial board. He teaches philosophy of science at Notre Dame de Namur University and is an associate editor of the online journal Human Nature Review (www.human


BIOLOGICAL DETERMINISM—the idea that human behavior is controlled in some significant way by our biological inheritance—has been a staple of ruling-class ideology for most of the past two centuries, but it has received a boost from important advances in genetic research and biotechnology that have taken place over the past fifteen years or so. In the past, genetic research was largely inferential and often speculative. Biologists and psychologists had no way of directly detecting an individual’s genes and so had to rely on indirect evidence. Now, however, that is beginning to change. New techniques allow us to directly map and manipulate an organism’s genes. This work culminated in the Human Genome Project, which between 1990 and 2003 sequenced the chemical base pairs and identified the 20,000 to 25,000 gene sequences in human DNA.

Certain stretches of DNA, called “polymorphisms” because they can occur in various forms, can be detected straightforwardly. If a polymorphism is consistently found to be inherited together with a certain trait—such as curly hair, for example—it may lie near a gene for that trait (in which case it is called a “marker”) or may even be the gene. In linkage studies, geneticists look for polymorphisms co-inherited with a trait in families in which the trait is common. Geneticists also carry out association studies, in which they compare the relative frequency of polymorphisms in two unrelated populations, one with the trait, one without it. Since the 1980s, genetic markers have been found for a variety of diseases, including Huntington’s disease, cystic fibrosis, and muscular dystrophy.

These are important scientific discoveries, although there are likely to be few practical short-term benefits for people who are at risk for these diseases, and indeed this research may open them up to various forms of employment and insurance discrimination. Nevertheless, scores of research teams are now attempting to use the same methods to locate genes—or at least genetic markers—for a variety of mental diseases and behavioral traits, including manic depression, schizophrenia, alcoholism, homosexuality, and even such old favorites as intelligence and criminality.2 This research has received enormous media attention, even—or perhaps particularly—when its claims verge on the absurd. A recent issue of Time magazine featured a cover story on “The God Gene.” “Does our DNA compel us to seek a higher power?” asked the headline. “Believe it or not, some scientists say yes.”3

It is perhaps not surprising, then, that the McGill University neuroscientist Evan Balaban has described research aimed at uncovering the genetic basis of human behavior as representing a “hierarchy of worthlessness.”4 Despite all the media hype, not one single research program in behavioral genetics has produced any credible results, and there is no reason to think that any of them will. There are at least three reasons for this.

First, it is rare for any significant characteristic of an organism to owe its existence to the action of a single gene. Genes are segments of DNA that make up the chromosomes found in all our cells, and which we originally inherited from our parents. The basic function of a gene is to carry information about the sequence of amino acids needed to construct a particular protein. Proteins are the basic building blocks for our bodies. Genes play a key role in the complex physiological processes that produce proteins, but they have their effects only in conjunction with other cellular components, in particular, enzymes. Enzymes are themselves proteins, whose amino acid sequences are coded in other genes. So, even in the production of a single protein, a variety of genes are indirectly involved.

In any case, for most interesting characteristics of an organism, the presence or absence of a single protein is not decisive. Even if the characteristic is genetically based, a large number of genes are likely to be involved, and this is particularly true of behavioral traits. Traits such as Huntington’s disease, which are caused by a single dominant gene, are the exception, not the rule. For this reason, the likelihood of finding markers for mental illnesses is very slim. Claims in the 1990s to have found genetic bases for conditions such as manic depression, schizophrenia, and alcoholism—all of which received extensive media coverage—were all later retracted (developments which the media largely ignored).5

The second reason for skepticism about human behavioral genetics is that in the case of many behavioral traits, there is little reason to think that they have any significant genetic basis, apart from the trivial fact that acquiring the trait must be compatible with one’s genetic inheritance. Take alcoholism, for instance. It is quite likely that in the right (or wrong) circumstances, any of us might become an alcoholic, just as in the right circumstances any of us can learn how to play chess, or become a revolutionary socialist.

It is sometimes pointed out that while our genes may not determine a particular outcome, they may make it more probable. It might be suggested, for instance, that some people have a greater genetic predisposition towards alcoholism than others. There is certainly a biological component in alcoholism, since it involves a single natural chemical that has specific effects on neurotransmitters and hormones, and it is possible, but by no means certain, that this has a genetic basis.6 But even if this genetic claim were true, it is not clear what the practical implications would be. A person with the relevant genetic constitution would have some greater degree of likelihood of becoming an alcoholic than someone without the relevant constitution if the two of them experienced exactly the same environmental conditions. But no two individuals ever do experience exactly the same environmental conditions, and even very slight differences in environment can result in huge differences in outcome. A 1999 study, for example, found that the same strains of mice could behave very differently in almost exactly the same circumstances, and concluded that almost undetectable environmental differences could make a very large difference to behavior.7 If anything, human behavior is likely to be even more sensitive to small environmental changes. If a thousand test subjects are put into the same stressful, alienated conditions, some will develop addictions while others won’t. But that does not tell us what will happen if we put the same people into a socially enriched environment instead. The same genetic constitution can be expressed in very different ways in different circumstances.

Third, and perhaps most importantly, for a trait to be genetically based, there must be clear, objective criteria to distinguish individuals that possess the trait and those that don’t. Even in the case of mental illnesses, though—which are the most likely behavioral traits to have some kind of genetic basis—it is notoriously difficult to provide such criteria. In the case of alcoholism, homosexuality, and criminality, there is even less reason to think that objective criteria exist. As an article in the Harvard Medical School Mental Review points out, for example, “As the social stigma of alcoholism becomes milder, more and more people are defined as alcoholics or become willing to define themselves that way.”8

To illustrate these problems, let’s look briefly at claims about the biological bases of crime and homosexuality, in part because these are two areas of research that have received extensive media attention.

Crime and violence

One of the enduring myths of biological determinism is the idea that crime and violence can be explained in genetic terms.9 In the nineteenth century, the Italian physician Cesare Lombroso proposed that germs of our evolutionary past remain dormant in our heredity, and that criminals are intellectual and physical throwbacks to our more primitive ancestors.10 Lombroso’s work is rightly ridiculed today as the crudest form of biological reductionism, yet research into the biological bases of crime still continues, with barely concealed racist undertones. The civil rights and Black and Chicano liberation movements of the 1960s and early 1970s pushed explicit racism to the margins of U.S. politics. In response, mainstream politicians increasingly began to use the issues of crime and “law and order” as ways to make coded appeals to racist white voters.11 Street crime was blamed on individual miscreants, rather than on underlying social conditions, where the individuals in question just happened to be disproportionately Black and Latino. Attempts to explain crime and violence in genetic terms have operated within the same framework.

In 1985, the criminologist James Q. Wilson and the psychologist Richard Herrnstein argued in their book Crime and Human Nature that efforts to explain street crime have given undue attention to social and economic factors. Instead, we should focus on individual differences, which often reflect biological and genetic differences, although different types of family upbringing also play a role. National Public Radio called the book a “blockbuster,” and it was given prominent and enthusiastic reviews in Time, Newsweek, US News & World Report, and the New York Times.

Wilson and Herrnstein’s book was also reviewed in the Heritage Foundation’s journal Policy Review by the then Democratic Mayor of New York City, Ed Koch. In an article titled “The Mugger and His Genes,” Koch praised the book’s “central thesis...that certain individual biological—indeed genetic—traits, when combined with an uncertain moral environment, produce criminal behavior. Moreover, these traits can barely be changed, if at all.” Koch continues:

Wilson and Herrnstein refute the prevailing notion that society somehow makes criminals.... The authors find only marginal roles for schools, neighborhoods, peer group values, television violence, and job market conditions as causes of crime. For the most part, their evidence is very persuasive. The people who try to blame civilization for criminal behavior look pretty foolish.12
The book’s recommendations have a familiar ring to them: more family responsibility, less permissiveness, more policing, and a greater emphasis on punishment. Wilson and Herrnstein admit that a relative increase in the Black homicide rate in Philadelphia over the past century compared with the rate for whites cannot plausibly be attributed to genetic changes. Nevertheless they claim that “purely genetic factors...may have made the average Black male more vulnerable to changing circumstances, such as the greater availability of handguns, alterations in economic opportunities, or the pressures of racial animosity.”13 In fact Wilson and Herrnstein are guilty of an elementary confusion between correlation and causation. It is true that skin color is positively correlated with being convicted for certain crimes, and skin color is, of course, genetically based. But the genes don’t cause the higher crime rate. That is a consequence of systematic discrimination, directed at people because they have a particular biologically inherited characteristic.

More generally, the idea that there might be a genetic basis for criminal behavior founders on the rather obvious fact that crime itself is a socially constructed category and that acts that are considered criminal in one context, are not considered crimes in another. As the Marxist biologist Steven Rose puts it:

I object to the reifying of the social complexity, giving it as it were a global name. I mean, is aggression the same thing that happens when a rat kills a mouse in a cage, which is the way it’s measured in the laboratory, or when a man beats his wife, or when there’s a pub brawl, or when there’s a pilot dropping a smart bomb on a bunker in Baghdad? These are not the same processes, they are socially different, and to call them all the same, assuming we have a unified mechanism for them is complicated enough. But also the same act under different circumstances is sometimes called a crime of violence and sometimes called a person acting in terms of social duty and responsibility. A soldier picking up a gun and shooting someone may be court-martialed for it, or may be regarded as a hero, but the biology of picking up the gun and shooting is identical. So to talk about aggression or violence as somehow encoded in the brain as if it actually ignores the social context in which we give these labels to things, is a sort of crude reductionism.14
Far from disappearing, however, attempts to explain crime and violence biologically are becoming more common. A PBS series on the mind told viewers in 1992, “Recent research suggests that even the acts of a serial killer may have a biological or genetic basis.”15 In February 1993, an episode of Donahue was advertised with the slogan “How to Tell If Your Child’s a Serial Killer!” On the show, Phil Donahue told the audience: “It is not hysterical or overstating it to say that we are moving toward the time when, quite literally, just as we can anticipate...genetic predispositions toward various physical diseases, we will also be able to pinpoint mental disorders which include aggression, antisocial behavior and the possibility of very serious criminal activity later on.”16 Later that year, the Chicago Tribune ran a series of articles on “Unlocking the Mind: Roots of Violence.” One article claimed that “Scientists...have found that aggression genes, those that raise a person’s propensity for violence, may be passed on to new generations. Some researchers believe that the increase in female criminal violence since the 1950s may be an early sign of how the genes of violence already are building up in the population.”17

In early 1992, the National Institute for Mental Health (NIMH) established the Violence Initiative, a project to study the biological roots of urban violence, focusing on inner-city Black youth. In February of that year, Frederick Goodwin, director of the NIMH, spoke to the National Mental Health Advisory Council, and compared inner-city youth to rhesus monkeys who only want to kill each other, have sex, and reproduce. Dr. Peter Breggin, director of the Center for the Study of Psychiatry and Psychology, warned that the project planned to target Black children with mood-altering drugs and other psychiatric techniques to control their behavior. Soon after the details became public, the National Movement to Stop the Violence Initiative was formed. As its co-chair, Loren Cress Love, put it: “Blacks were brought to America in violence, Native Americans were decimated by violence and people of color worldwide are victims of violence by whites. If we test people who are violent, blacks aren’t the ones to be tested.”18 As part of the initiative, in October 1992 the National Institutes of Health and the Human Genome Project organized a conference on “Genetic Factors in Crime.” The conference was only canceled after Dr. Breggin criticized the event at a public meeting of the Congressional Black Caucus. As a result of the publicity, the Violence Initiative was shelved, although individual component programs continued to be funded by the federal government. The “Genetic Factors in Crime” conference, for example, eventually took place in a modified form at the University of Maryland in 1995.19

A similar conference on the genetic basis of aggression was held in July 2004 at the Royal Society of Medicine in London. According to one of the participants, Donald Pfaff of New York’s Rockefeller University, studies of the genetic basis of animal behavior have opened the possibility of creating new drugs to control antisocial behavior. “One question we’re looking at is opportunities for pharmacogenomics. The use of cleverly designed drugs to control inappropriate aggression and violence [could] bring that individual into a range where normal social controls, including a good family environment and good school environments, can work.” Another participant, Randy Nelson, a geneticist at Ohio State, said individuals who exhibit impetuous behavior would be likely targets. “If there was some sort of pharmacological treatment that could prevent that sort of impulsive aggressiveness from occurring, that would probably be ideal.” Nelson added that the same drugs could be used for preventing dogs from biting people.20 So once again human actions that take place in complex social contexts are lumped together with animal behaviors as if they can be explained and dealt with in the same way. This whole approach would be laughably simplistic if the potential social consequences were not so horrific.

What is most striking about the supposedly scientific research into the roots of crime, violence, and anti-social behavior is the extent to which it is based on unquestioned right-wing assumptions. The focus is on the question of why some individuals rather than others turn to crime and violence in certain social conditions, rather than on the social conditions themselves, which are simply taken for granted. Yet the best single predictor for levels of so-called street crime is the unemployment rate, and it is social conditions, not genetic or biological factors, that explain why crime levels are higher in one time and place as opposed to another. As the philosopher and criminologist Jeffrey Reiman puts it,

the social order (shaped decisively by the economic system) bears responsibility for most of the crime that troubles us. This is true of all classes in society, because a competitive economy that refuses to guarantee its members a decent living places pressures on all members to enhance their economic position by whatever means available. It degrades and humiliates the poor while encouraging the greed of the well off. Nevertheless, these economic pressures work with particular harshness on the poor because their condition of extreme need and their relative lack of access to opportunities for lawful economic advancement vastly intensify for them the pressures toward crime that exist at all levels of our society.21
Research on the genetics of crime and violence not only ignores social conditions, it also focuses almost exclusively on street crimes committed by those at the bottom of the social order. Yet white collar and corporate crime, together with many business activities that are perfectly legal under capitalism, cost ordinary citizens far more in financial terms and are responsible for many more deaths each year.22 And of course the greatest violence in our society is unleashed by governments in times of war. Despite this there is no suggestion from genetic researchers that new behavior-controlling drugs should be designed and administered to members of the Bush administration or to the executives of multinational corporations. This reflects deeply ideological and class-based definitions of crime and violence. This point was made clearly by Marx’s friend and collaborator Frederick Engels in the nineteenth century.

When one individual inflicts bodily injury upon another such that death results, we call the deed manslaughter; when the assailant knew in advance that the injury would be fatal, we call his deed murder. But when society places hundreds of proletarians in such a position that they inevitably meet a too early and an unnatural death, one which is quite as much a death by violence as that by the sword or bullet; when it deprives thousands of the necessaries of life, places them under conditions in which they cannot live—forces them, through the strong arm of the law, to remain in such conditions until that death ensues which is the inevitable consequence—knows that these thousands of victims must perish, and yet permits these conditions to remain, its deed is murder just as surely as the deed of the single individual; disguised, malicious murder, murder against which none can defend himself, which does not seem what it is, because no man sees the murderer, because the death of the victim seems a natural one, since the offence is more one of omission than of commission. But murder it remains.23
Attempts to explain crime and violence in genetic terms act as a distraction from these realities. They blame disadvantaged individuals while turning attention away from the injustices of existing social structures and from the destructive and violent actions of the powerful.

The “gay gene”

Recent research into the possible biological basis of sexual orientation has generally had a very different kind of motivation, being intended not to support the status quo but to challenge it. The idea that homosexuality has a genetic basis became prominent in the early 1990s as a result of three new studies. In 1991 Simon LeVay, a neurobiologist at San Diego’s Salk Institute claimed to have found differences between the brain structures of gay men who had died of AIDS and “presumed heterosexuals.”24 That same year, Michael Bailey of Northwestern University and Richard Pillard of Boston University, published a study claiming that there was a much higher rate of homosexuality among identical twin brothers than among fraternal twin brothers, and among non-twin and adoptive brothers of the twins.25 Finally, in 1993 a team at the National Cancer Institute led by Dean Hamer, claimed to have found a set of genetic markers shared by a number of gay brothers.26

LeVay was quite open that his research was motivated by the hope that if being gay was shown to be biologically based, it would help to make it more socially acceptable. The same thought was expressed by Robert Bray, the head of public information for the National Gay and Lesbian Task Force: “It points out that gay people are made this way by nature. It strikes at the heart of people who oppose gay rights and who think we don’t deserve our rights because we’re choosing to be the way we are.”27 But the idea that demonstrating a biological basis for sexual orientation will end homophobia is a fantasy. Skin color is unquestionably biologically based, but that hasn’t ended racism. In fact, after stories of LeVay’s research appeared in the press, there were reports that some health clinics had received calls from prospective parents wanting to know if fetuses could be tested for homosexuality and aborted. A report on the Hamer team study in the London Daily Mail was headlined “Abortion Hope After ‘Gay Genes’ Findings.”28 If homosexuality really were shown to be biologically based, homophobes would simply treat being gay as a genetic defect. The Nazis, after all, did believe that homosexuality is biologically based, but that did not stop them from exterminating gay people. LeVay, however, has dismissed this comparison, saying “Those who look to history are condemned to repeat it.”29

But in any case, all the published research had serious methodological flaws and did nothing to show that the supposed biological basis existed. LeVay claimed that an area of the hypothalamus in gay men and straight women is smaller than in straight men, and that the small size is linked to a sexual preference for males. But his sample size was extremely small, little was known about the actual sexual activity of the supposed straight men and women whose brains were examined, and while the size of the relevant area of the hypothalamus was indeed smaller on average in the gay men, the size range in the two groups overlapped almost completely. In addition, the gay men had all died of AIDS, a disease that causes brain degeneration. Finally, even if the brain differences were significant, there is no reason to think that they were the cause, rather than the effect, of sexual orientation. LeVay himself made this final point in his paper, but in explaining his work to the media he emphasized the idea that the brain structure was the cause.30 Even if that were true it would still not show a genetic basis for sexual orientation, since brain development is not dictated solely by the genes, but depends equally on the environment.

Bailey and Pillard’s twin study—which was intended to demonstrate the importance of genetics—was equally unconvincing, since it failed to control for the ways in which twins are treated differently from ordinary siblings. Moreover, the sample they studied may have been a highly biased one, since the individuals involved were recruited by ads placed in gay publications. As the Harvard biologists Ruth Hubbard and Elijah Wald point out:

men with gay brothers might well have been more likely to participate than men with brothers who were straight, especially if the brothers were homophobic or if the gay men were not “out” to their families. Since many people believe that homosexuality is genetic, a straight man who has a homosexual identical twin might well feel that his own sexual orientation was “suspect,” and might find the subject threatening. Conversely, identical twins who are both gay might find the subject interesting, and be eager to participate in a study.31
Finally, the Hamer team claimed to have found that thirty-three of the forty pairs of gay brothers in its study shared certain DNA sequences on their X chromosome. They reasoned that if brothers who have specific DNA sequences in common are both gay, these sequences are genetic markers for homosexuality. But there are obvious problems with this conclusion. The survey sample was very small, and not all the subjects had the marker. The study did not find a single genetic marker, but a variety of different similarities between different pairs. And there was no control experiment to check for the presence of these markers among heterosexual brothers of the gay men studied. “It is surprising that the correlation found in this research warranted publication without these controls, especially in as influential a journal as Science,” Ruth Hubbard told one reporter. “Past claims of the discovery of genetic markers for behavioral traits such as schizophrenia, manic depression, and alcoholism have not withstood further investigation. The reason the gay gene ‘discovery’ is big news is not that it is any more promising than the others but that the debate on homosexual rights is hot.”32 When the Hamer study was first published it was reported on the front page of the New York Times. But when Canadian researchers reported in 1999 that they had been unable to replicate Hamer’s results, the newspaper relegated their results to page seventeen.33

But the major problem with all this research is that it assumes without argument that sexual identities are unchanging features of human behavior, with a small minority at any one time being exclusively homosexual. In fact, sexual identities are socially and historically constructed.34 The idea that attraction to the same sex is the exclusive characteristic of a small minority, and that people should be defined in terms of their sexual activities, only became current in the late nineteenth century. The claim that such a socially constructed category has a biological explanation is thus highly implausible. As the historian of sexuality Jennifer Terry has remarked about LeVay’s work:

LeVay, like many other scientists working on matters related to sexuality, went to considerable lengths to measure an area of the brain where “significant” differences between presumably heterosexual and homosexual men are no larger than a grain of sand. But he used no precision in his measurement of social variables—things as analytically complex as sexual orientation, sexual desire, and gender identification. Typically, these social variables are never measured by biological scientists; instead, like LeVay, they substitute simple folk understandings for complex analytical constructs and systems. And these folk understandings tend to be crystallizations of [the] dominant ideology regarding sex and sexuality.35


The claims of the genetic determinists are not only false, they are dangerous. They will be and are being used to justify right-wing policies on a whole range of social issues, from crime to education. Even more frightening is the possible emergence of new forms of eugenics.36 Daniel Koshland, the former chief editor of Science magazine, has asked, for example,

Is there an argument against making superior individuals? Not superior morally, and not superior philosophically, just superior in certain skills: better at computers, better as musicians, better physically. As society gets more complex, perhaps it must select for individuals more capable of coping with its complex problems.37

Koshland’s views remain extreme—the vast majority of scientists would reject them—but the increasing tendency to see social problems in genetic terms has already begun to move society in this direction.38 There are, for instance, growing pressures on pregnant women to permit genetic tests of their fetuses and to abort those that are considered “defective.”39

Even areas of genetic research that are yielding real advances in knowledge may, under capitalism, hurt rather than help most people. Knowing the genetic basis of various medical conditions may in the long run help to find cures. But in the immediate future it is more likely to lead to new forms of employment and insurance discrimination.40 The situation is similar to other technological advances. In a socialist society, increased mechanization would allow necessary work to be performed more efficiently and would extend human freedom. Under capitalism it produces mass unemployment and millions living in poverty.

None of this, though, has to be this way. Genuine biological knowledge makes clear that the injustice, inequality, and irrationality of capitalist society are not inevitable, and that a very different kind of social order is possible. Biological determinists maintain that our biological inheritance places relatively tight constraints on possible forms of human behavior. By contrast, the actual history of human evolution points to a very different picture of human nature. The most distinctive biological feature of human beings is our large brain, which developed when our early ancestors stopped living in trees and began walking upright, thus freeing their hands to produce and use more complex tools. Tool using created evolutionary pressure for greater brain development, which in turn brought increased intelligence and the emergence of language. This is the basis for the enormous flexibility of human behavior. The great evolutionary biologist Stephen Jay Gould put it well:

Human uniqueness lies in the flexibility of what our brain can do. What is intelligence, if not the ability to face problems in an unprogramed (or, as we often say, creative) manner? If intelligence sets us apart among organisms, then I think it probable that natural selection acted to maximize the flexibility of our behavior. What would be more adaptive for a learning and thinking animal: genes selected for aggression, spite, and xenophobia; or selection for learning rules that can generate aggression in appropriate circumstances and peacefulness in others?41
It is the human ability to learn and to pass on newly acquired knowledge and behavior to future generations that makes it impossible to understand the complexities of human society in biological terms, even though we are biological creatures.

Human uniqueness resides primarily in our brains. It is expressed in the culture built upon our intelligence and the power it gives us to manipulate the world. Human societies change by cultural evolution, not as a result of biological alteration. We have no evidence for biological change in brain size or structure since Homo sapiens appeared in the fossil record…. All that we have done since then—the greatest transformation in the shortest time that our planet has experienced since its crust solidified nearly four billion years ago—is the product of cultural evolution.… In short, the biological basis of human uniqueness leads us to reject biological determinism. Our large brain is the biological foundation of intelligence; intelligence is the ground of culture; and cultural transmission builds a new mode of evolution more effective than Darwinian processes in its limited realm—the “inheritance” and modification of learned behavior.42
These considerations from evolutionary biology are reinforced by what we know about brain development in the growth of individual humans. While some peripheral structures, such as sensory cells, are genetically specified, most brain structures develop as the result of brain cell proliferation followed by a process of “pruning.” While the initial process of proliferation is under genetic control, the process of brain-cell pruning depends on interaction between cells and the environment. Thus the cortical structures we end up with are not genetically specified but mainly shaped by our environment.43 The human brain is thus enormously flexible. Its very plasticity is its most distinctive biological feature. “As a result,” comments the French philosopher Dominique Lecourt, “humans, more than any other animal species can free themselves from the constraints of nature. In other words, people’s nature consists in not having a nature in the same sense that other animals do.”44 The claim is not that there are no biological limits to human behavior, but that our biology has made a much greater range of behaviors possible than in other species. On this, let us give the final word to Gould:

Violence, sexism, and general nastiness are biological since they represent one subset of a possible range of behaviors. But peacefulness, equality, and kindness are just as biological—and we may see their influence increase if we can create social structures that permit them to flourish.45

1 Part one of this article appeared in Phil Gasper, “Is Biology -Destiny?” International Socialist Review 38, November–December 2004.

2 Media reports in the past few months have announced genetic bases for anxiety in women, spite, smoking, and infidelity. See “Gene Makes Women Prone to Anxiety,” BBC News, August 10, 2004, available at; James Reynolds, “Spite? It’s All Down to the Nasty Genes,” The Scotsman, September 3, 2004, available at scitech.cfm?id=1035142004; “New Gene Linked to Smoking -Addiction,” Agence France Presse, November 23, 2004, available at; and “Genetic Factors Influence Female Infidelity-Study,” Reuter’s, November 24, 2004, available at http:// =6909742.

3 Jeffrey Kluger, “Is God in Our Genes?” Time, October 25, 2004. The article was prompted by Dean Hamer’s book The God Gene: How Faith Is Hardwired into Our Genes (New York: Doubleday, 2004). Hamer first came to public attention in the early 1990s for claiming that homosexuality is genetically based, a case that I discuss below. The idea that theism has a biological basis is difficult to reconcile with the fact that levels of religious belief can fluctuate dramatically from one generation to another. And it is plain silly to think that, say, higher levels of atheism in Western Europe as compared to North America have a biological explanation.

4 Quoted in John Horgan, “Eugenics Revisited,” Scientific American, June 1993, 131.

5 The claim that there is a gene for alcoholism was made in 1993 by researchers at the University of California, San Francisco. They just happened to work in the Ernest Gallo Clinic and Research Center, which receives millions in funding from one of California’s biggest manufacturers of cheap wines! See Dorothy Nelkin and M. Susan Lindee, The DNA Mystique: The Gene as a Cultural Icon (New York: W.H. Freeman, 1995), 162. Research on alcoholism at the Center continues.

6 It is not certain because the biological factors could be an effect rather than one of the initial causes of the condition.

7 John C. Crabbe, Douglas Wahlsten, and Bruce C. Dudek, “Genetics of Mouse Behavior: Interactions with Laboratory Environment,” Science 284 (1999), 1,670–72.

8 Lester Grinspoon and James B. Bakalar, “The Nature and Causes of Alcoholism,” Harvard Medical School Mental Health Review, No. 2, 1990, 1–6.

9 See Garland E. Allen, “The Biological Basis of Crime: An Historical and Methodological Study,” Historical Studies in the Physical and Biological Sciences, Vol. 31, No. 2 (2001), 183–222.

10 See Stephen Jay Gould, The Mismeasure of Man (New York: Norton, 1981), 122–45.

11 See Phil Gasper, “Cruel and Unusual Punishment: The Politics of Crime in the United States,” International Socialism 66, Spring 1995, available online at isj66/gasper.htm.

12 Policy Review, 35 (Winter 1986), 1–28.

13 James Q. Wilson and Richard J. Herrnstein, Crime and Human Nature (New York: Free Press, 1998), 472.

14 Interview on BBC Radio 3, December 23, 2003. The transcript is available at programmes/ belief/ scripts/steven_rose.shtml.

15 Nelkin and Lindee, 84.

16 Quoted in Horgan, “Eugenics Revisited,” 123.

17 “Unlocking the Mind: Roots of Violence,” Chicago Tribune, December 14, 1993. The psychologist Jeffrey Goldstein found that the media systematically cover studies that offer evidence of genetic explanations of violence, but are less interested in research on the influence of social and economic conditions. When the American Psychological Association, the American Anthropological Association, the International Society for Research on Aggression, and Psychologists for Social Responsibility endorsed a statement rejecting the idea that violence is biologically determined, one journalist responded: “Call me when you find the gene for war.”

18 Quoted in Salim Muwakkil, “Do Genes Cause Crime?” In These Times, December 28, 1992.

19 See Dr. Peter Breggin, “Campaigns Against Racist Federal Programs by the Center for the Study of Psychiatry and Psychology,” Journal of African American Men Vol. 1, No. 3 (Winter 1995/96), 3–22, available online at

20 David Adam, “Gene Scientists Plan Aggression Drug,” Guardian (UK), July 20, 2004, available online at uk_news/story/0,3604,1264938,00.html.

21 Jeffrey Reiman, The Rich Get Richer and the Poor Get Prison: Ideology, Class, and Criminal Justice, 7th ed. (Boston: Allyn and Bacon, 2004), 7.

22 See Reiman, ch. 2.

23 Frederick Engels, The Condition of the Working Class in England (New York: Granada, 1969), 126–27. (Originally published in German in 1845.)

24 Simon LeVay, “A Difference in Hypothalmic Structure between Homosexual and Heterosexual Men,” Science 253 (1991), 1733-39. Also see Simon LeVay, The Sexual Brain (Cambridge, MA: MIT Press, 1993).

25 Michael Bailey and Richard Pillard, “A Genetic Study of Male Sexual Orientation,” Archives of General Psychiatry, 48 (1991), 1,089–96.

26 Dean Hamer, “A Linkage Between DNA Markers on the X Chromosome and Male Sexual Orientation,” Science 261 (1993), 321–27. Also see Dean Hamer and Peter Copeland, The Science of Desire (New York: Simon and Schuster, 1994).

27 Quoted in Darrell Yates Rist, “Are Homosexuals Born That Way?” Nation, October 19, 1992.

28 “Abortion Hope After ‘Gay Genes’ Findings,” Daily Mail (UK), July 16, 1993.

29 Speech at a symposium on “The Homosexual Brain,” City -College, New York, December 9, 1991. Quoted in Nelkin and Lindee, 123.

30 Jonathan Mark, What it Means to be 98% Chimpanzee: Apes, People, and their Genes (Berkeley: University of California Press, 2002), 113–14.

31 Ruth Hubbard and Elijah Wald, Exploding the Gene Myth, revised edition (Boston: Beacon Press, 1997), 97.

32 New York Times, August 2, 1993.

33 Jonathan Mark, 125.

34 See Edward Stein, The Mismeasure of Desire: The Science, Theory, and Ethics of Sexual Orientation (New York: Oxford University Press, 1999).

35 “The Seductive Power of Science in the Making of Deviant Subjectivity,” in Vernon Rosario II (ed.), Science and Homosexualities (New York: Routledge, 1996).

36 See part one of this article for a discussion of the eugenics movement in the U.S. in the first half of the twentieth century.

37 “The Future of Biological Research: What Is Possible and What Is Ethical?” MBL Science, Vol. 3, 1988-1989, 10-15. Quoted in Hubbard and Ward, 116.

38 See Troy Duster, Backdoor to Eugenics, 2nd ed. (New York: Routledge, 2003).

39 Hubbard and Wald, ch. 3. Hubbard writes: “I unequivocally support a woman’s right to terminate a pregnancy, whatever her reasons. Despite the problems involved in prenatal testing, a prospective mother who decides to be tested must be able to act on the results in whatever ways fit her circumstances. That means that she must have the right either to abort or to continue the pregnancy, without external pressure. Unfortunately, such pressures are everywhere. Many women who wish to have an abortion cannot get one, for financial or other reasons. Conversely, many women who can pay for tests are considered irrational if they decide not to have an abortion when the fetus they are carrying has been diagnosed as having a disability.” (30)

40 See Hubbard and Wald, ch.10, and Joseph Alper et al. (eds.), The Double-Edged Helix: Social Implications of Genetics in a Diverse Society (Baltimore: Johns Hopkins University Press, 2002).

41 Gould, 331.

42 Ibid., 324–25.

43 See David Buller and Valerie Gray Hardcastle, “Evolutionary Psychology, Meet Developmental Neurobiology: Against Promiscuous Modularity,” Brain and Mind 1 (2000), 307–25.

44 “Introduction” to Alain Prochiantz, How the Brain Evolved (New York: McGraw Hill, 1992), 17.

45 Stephen Jay Gould, “Biological Potentiality vs. Biological Determinism,” in Ever Since Darwin: Reflections in Natural History (New York: Norton, 1977), 257.

Marxism, Biology and Human Nature

HUMAN BEINGS are not naturally violent, selfish, competitive, greedy, or xenophobic, it is not natural for human societies to be organized hierarchically or for women to have lower social status than men, and capitalism does not exist because it uniquely reflects human nature. But to make such claims is not the same as saying—as the evolutionary psychologist Steven Pinker seems to assume—that the human mind is simply a “blank slate” or that there are no biological constraints on human behavior.1

It is true that in different social and historical circumstances, human behavior and psychology can vary dramatically, just as in different physical circumstances, water can be a solid, a liquid, or a gas. But that does not mean that human beings are infinitely malleable or that there are no biological constraints on human behavior. As Stephen Jay Gould once noted, “We would lead very different social lives if we photosynthesized (no agriculture, gathering, or hunting—the major determinants of our social evolution) or had life cycles like…gall midges,” which devour their mothers’ bodies from the inside, and which are in turn eaten by their own offspring within a few days.2

The range of potential human behaviors has limits, and a description of those limits and their basis in human biology and psychology would be a description of human nature. In fact, if such limits did not exist, then it would be possible for there to be class societies in which the majority of the population was socially conditioned to be permanently reconciled to its exploitation and oppression. But the whole history of class societies is a refutation of that idea.

No one was more aware of this than Marx, which is why from his earliest writings he condemns capitalism as inhumane—a society in which most human beings cannot live satisfying lives, engage in fulfilling work, or relate in satisfactory ways to other people or to the rest of the natural world. In other words, capitalism frustrates basic human needs and human nature. In capitalist society,

Labor is external to the worker, i.e. it does not belong to his essential being;…in his work, therefore, he does not affirm himself but denies himself, does not feel content but unhappy, does not develop freely his physical and mental energy but mortifies his body and ruins his mind. The worker therefore only feels himself outside his work, and in his work feels outside himself. He is at home when he is not working, and when he is working he is not at home. His labor is therefore not voluntary, but coerced; it is forced labor. It is therefore not the satisfaction of a need; it is merely a means to satisfy needs external to it. Its alien character emerges clearly in the fact that as soon as no physical or other compulsion exists, labor is shunned like the plague….

As a result, therefore, man (the worker) no longer feels himself to be freely active in any but his animal functions—eating, drinking, procreating, or at most in his dwelling and in dressing-up, etc.; and in his human functions he no longer feels himself to be anything but an animal. What is animal becomes human and what is human becomes animal.3

Biological determinists want us to believe that human talent is naturally scarce so that the hierarchies that exist in capitalist society reflect human nature. By contrast, Marxists argue that capitalism is not natural and that the artificial limits imposed on human development by our current forms of social organization are the real limits to our potential.

Under capitalism, most people lack control over central areas of their lives and are able to exercise their capacity to engage in creative activity only in limited ways, if at all. That results in a vast squandering of human talent. For one small example, think of the large number of gifted artists there are on death rows around the country. These are people who previously had little or no chance to develop these skills, but who flourish once they have the opportunity. The tragedy is that in our society this only takes place in a condemned cell where they await execution.

Examples of this kind could be multiplied many thousand times and are the basis for thinking that under socialism, not only exploitation and oppression would be abolished, but there would be a huge flowering of human creativity. As the Russian revolutionary Leon Trotsky put it, in a socialist society,

Man will make it his purpose to master his own feelings, to raise his instincts to the heights of consciousness, to make them transparent, to extend the wires of his will into hidden recesses, and thereby to raise himself to a new plane…. The average human type will rise to the heights of an Aristotle, a Goethe, or a Marx. And above this ridge new peaks will rise.4

1 See part one of this article for a discussion of Pinker and evolutionary psychology,

2 Gould, “Biological Potentiality vs. Biological Determinism,” in Ever Since Darwin, 252–53. On the reproductive cycle of gall midges, see “Organic Wisdom, or Why Should a Fly Eat Its Mother from Inside,” in Ever Since Darwin, 91–96. Elsewhere, Gould gives a longer list of biological constraints: “Consider our narrow range of average adult size and the consequences of living in the gravitational world of large organisms, not the world of surface forces inhabited by insects…. Or the fact that we are born helpless (many animals are not), that we mature slowly, that we must sleep for a large part of the day, that we do not photosynthesize, that we can digest both meat and plants, that we age and die. These are all results of our genetic construction, and all are important influences upon human nature and society.” (The Mismeasure of Man, 328.)

3 Karl Marx, Economic and Philosophic Manuscripts of 1844 in Robert C. Tucker (ed.), The Marx-Engels Reader 2nd ed. (New York: Norton, 1978), 74. For further discussion of Marx’s views on human nature, see Norman Geras, Marx and Human Nature: Refutation of a Legend (New York: Verso, 1983) and Sean Sayers, Marxism and Human Nature (New York: Routledge, 1998).

4 Leon Trotsky, Literature and Revolution (Ann Arbor, MI: University of Michigan Press, 1960), 255–56. (Originally published in Russian in 1924.)

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