Chapter 7 Sex and the Selfish Genes

In the abortion debate, the labels "pro-life" and "pro-choice," though individually unfair and tendentious, together form a useful balance. "Pro-life" is unfair and tendentious because pro-choice people, too, are often in favor of life-- they support laws against infanticide and prefer peace to war-- while pro-life people might be, if anything, more likely than pro-choice people to favor certain wars, eat meat, and even support the death penalty. They favor the preservation of life over other considerations when they consider it appropriate, and not otherwise. By the same token, pro-life people support lots of freedom of choice, from whether to marry to whether to worship God to whether to take a second slice of butter, while pro-choice people oppose some choices, such as, again, infanticide, or maybe littering in the park. Indeed, if anything, pro-lifers are more likely to be economic conservatives who would favor deregulation and freedom in business, while pro-choicers are often left-liberals who favor more regulation for the common good. Pro-life and pro-choice people both favor choice when they consider it appropriate, and not otherwise. Still, the labels are substantive enough to sum up, in a very crude and abbreviated way, the moral goals that motivate the two sides on the issue in question, and since their tendentiousness balances out, jointly the terms are not only convenient but fair to both sides.

Let me suggest a similar pair of labels for the two sides of the marriage debate. Supporters of same-sex marriage have chosen theirs: “marriage equality.” Of course, opponents of same-sex marriage support marriage equality, too. They support the right of both straights and gays to marry someone of the opposite sex. If gays do not wish to exercise this right, it is not thereby taken away from them. And straights should be as unable as gays to marry someone of the same sex. Equal rights. Meanwhile, supporters of same-sex marriage would recognize the right to marry someone of the same sex, but not someone underage, or already married, or dead, or a sibling. Both sides favor the right to marry when they consider it appropriate, and not otherwise. The phrase “marriage equality” is question-begging; it asserts that people are equally entitled to _________, but provides no warrant for filling in the blank one way rather than another. As a matter of logic, “marry a consenting single, living, adult, non-related individual of the opposite sex” is as valid a way to fill in the blank as “marry a consenting single, living, adult, non-related individual,” full stop. Still, the phrase “marriage equality,” suggesting an equal right to marry the person you love, seems to have a certain intuitive force, and it is no more tendentious than “pro-life” or “pro-choice.” It does justice to the moral goals that motivate the, well, marriage-equality cause.

As compensation for endorsing the phrase “marriage equality,” I suggest that opponents of same-sex marriage have the right to adopt our own tendentious label, and I propose the phrase “marriage realism.” The main common idea among opponents of same-sex marriage (and David Blankenhorn is the exception that proves the rule) is that marriage is not a mere arbitrary legal construct but is real, with a reality deeper than any state-endorsed label. The government has at most limited power to define what is and is not marriage, because marriage has a fundamental, pre-political basis in human nature. If the government calls a same-sex union marriage, it still will not really be marriage. The government will simply be misusing a word. If the population acquiesces in the redefinition of the word “marriage,” that word will simply have come to refer, inconveniently, to two different things, marriage and state-backed gay relationships.

Now, it is true that same-sex marriage supporters, too, believe that marriage is in some sense a reality. After all, even a legal construct has its own kind of reality. And some same-sex marriage supporters do seem to feel vaguely that marriage has a reality independent of the state, though they have trouble explaining clearly and agreeing on what that reality consists in. So supporters of same-sex marriage could make some claim to be "marriage realists," too. That is why the term is tendentious.

Also, one can oppose same-sex marriage without being a marriage realist. All the arguments I presented in Part I were independent of the claim that marriage is anything more than a legal construct. They explain, not why same-sex marriage is a metaphysical impossibility, but why extending the legal institution of marriage may be a bad idea. Here in Part II, I will write as a marriage realist, and try to explain what marriage really is, and why it must mean a man and a woman. From that follows another reason not to recognize same-sex marriage: in doing so, the state is guilty of untruth, and is forcing its citizens to perjure themselves, or at least encouraging them to introduce a confusing fiction into the language.

Jonathan Rauch coined a brilliant phrase when he called marriage “the Brooklyn Bridge of social engineering.” It encapsulates much of Rauch’s argument, and his error, with marvelous succinctness. To see why, one must know the backstory of the phrase “social engineering." It usually has negative connotations, as for example in the writings of the influential historian Paul Johnson, whose 1983 world history Modern Times uses “social engineering” as a catch-all term for most of the man-made catastrophes of the 20th century, from Soviet socialism to Nazi race policy to South African apartheid to Prohibition in the US (a much milder example, of course). Social engineering has the connotation of top-down control, of revolutions from above, of treating people as means to ideological ends, of ignoring human rights and curtailing liberty, of trying to remake human nature by force. Social engineering stands over against the heritage of tradition, the natural development of human potentialities, and the spontaneous order of the market. Rauch presumably knows all this, and in using the phrase “social engineering” with positive connotations, there is an element of irony, and of surprise at how marriage and all that it does for human happiness and civilization are achieved with so little deliberate planning or direct use of force. Social engineering usually doesn't work; this time it did! Again and again, social engineering is born of hubris and bears the fruit of catastrophe, ends in failure and is recalled with shame, yet marriage, somehow, stands alone amidst this wasteland, thoroughly satisfactory and successful. But the explanation is simple. Marriage is not the Brooklyn Bridge of social engineering. It is not social engineering at all. It is a part of human nature.

It is possible for us to establish this, because in the last few decades, sociobiology, also known as evolutionary psychology, has emerged as a new basis for making firm claims about human nature.

Intellectual history can sometimes seem like a meaningless flux, the pastime of the privileged intelligentsia, with schools of thought reacting against one another and deteriorating, each judging the others fallacious, then being condemned and forgotten by others which succeed them, while the common sense of the common people flows like a river under them all, carrying humanity forward in spite of all these superfluous speculations. Every now and then, however, really true and useful ideas do come along. For example, the idea of demand, supply, and equilibrium in economics may be said, with a little poetic license, to have won the Cold War and saved freedom in the world. In fact, I'll take the liberty of a long digression about how the ideas of market economics foiled socialism, because it serves as a useful historical parallel to the way sociobiology stands ready, if taken seriously, to foil the redefinition of marriage.

In the late 19th-century, private property was coming to be regarded as a notion as obsolete and pernicious as absolutist divine right monarchy. It was the legitimating ideology of an exploitative bourgeois class. The future belonged to socialism, which would sweep away private property and all other self-serving superstitions fostered by the money elite to keep their power, and reorganize human affairs on a rational basis for the benefit of all. Fortunately, at the same time, the “marginal revolution” in economics was purifying the old classical economics, pioneered by Adam Smith and David Ricardo, of certain fallacies, especially the “labor theory of value,” and articulating its insights in a new and more logically compelling way. Neoclassical economics would emerge as a worthy rival to socialism.

The central insight of the marginal revolution is captured in the supply-and-demand chart which is now taught in every introductory economics class, and which shows how the price moves to equilibrate demand and supply, efficiently allocating resources without government intervention. All the government has to do is to protect property rights. The marginal revolution did not stop the Bolshevik socialists and National Socialists (i.e., Nazis) from taking power, or the Labor Party from crippling Britain with high taxes and big government for a generation, or the New Deal from exacerbating the Great Depression in America. But it encouraged resistance, provided a ready diagnosis when all the various socialist experiments proved disappointing, and showed the way out of them, back into capitalist prosperity. The irony is that many of the major contributors didn’t exactly intend to legitimize capitalism. Leon Walras, a founder of the marginal revolution, considered himself a socialist. Alfred Marshall, another founder, spoke in favor of the trade unions, which characteristically impede market-based wage-setting. Joan Robinson, who provided crucial elucidation of the nature of market competition, was a Communist and an admirer of North Korea. Arthur C. Pigou, a crucial contributor to the theory of market efficiency, was such a believer in rich-to-poor redistribution that he was plausibly accused of being a Soviet agent. Frank Knight, a leading light of what later became the arch-free-marketeer Chicago School, gave a speech in 1932 encouraging his audience to vote Communist, albeit somewhat flippantly. Joseph Schumpeter, a visionary theorist of capitalistic technological progress, did not think capitalism could survive and said that “of course” socialism can work. Paul Samuelson, the greatest pioneer of mathematical formalism in economics, favorably cited Soviet socialism as a viable alternative to capitalism in his influential textbooks. Not until Milton Friedman did the “neoclassical” economics born in the marginal revolution find a major, mainstream champion who really believed in the pro-capitalist message which, in retrospect, the theory seems tailor-made to promote. Moreover, few of these economists liked the Christian conservative order of which, by supplying a defense of property rights, they were to some extent the de facto allies. Frank Knight mocked Christianity as absurd, and Knut Wicksell, a pioneering theorist of money and credit, was briefly imprisoned for blasphemy after a speech satirizing the Immaculate Conception. Milton Friedman was Jewish. But the logic of economic theory accomplished what the prejudices of its expositors made them reluctant to wish for, and by the time the Soviet Union fell, economics could hand down an authoritative judgment on what that fall meant. Socialism doesn't work, or at least, not nearly as well as market capitalism.

As the socialist revolutions of the early 20th century doubted or denied property rights, the sexual revolution of the 1960s and afterwards has doubted or denied marriage. That is, a few radicals rejected marriage altogether, but society as a whole has let it persist, while weakening its authority and altering its meaning. No-fault divorce has made marriage less binding and permanent. Divorce is not only legal but more socially acceptable than it was. A far larger share of children are born outside wedlock. It is normal for unmarried couples to cohabit. Sex outside marriage is routinely represented in movies as normal and morally unproblematic. Yet at the same time, a new science has been born, sociobiology, whose tendency, though perhaps most of its leading expositors will resist admitting this, is basically to legitimate gender differentiation and supply a new, or rather a renovated version of the old, case for marriage. Sociobiology provides a firm basis for marriage realism.

Sociobiologists are unlikely allies for traditional family values. Some, like Richard Dawkins, Daniel Dennett, and E.O. Wilson, are vigorous propagandists for an atheistic and materialistic worldview. Indeed, I should clarify immediately that I am not endorsing sociobiology as a comprehensive theory of human nature, which is what many of its champions try to make it. Much of sociobiology is little better than speculative hand-waving. Sociobiology is not very insightful on aesthetics, religion, morality and virtue, or the mind, just to take a few examples. But it is very insightful about human sexuality and gender, where a consensus has been emerging, firmly grounded in evolutionary logic, confirmed by physiological, psychological, and anthropological evidence, and largely confirming common sense. I suspect that it largely confirms the truth of many gender stereotypes, only I was raised in a hotbed of liberal political correctness (Boulder, Colorado) where stereotypes were taboo. I was therefore largely cut off from this useful record of accumulated experience about patterns of human behavior, so I am ill-equipped to judge the extent to which sociobiology confirms it. But I do recognize confirmations of the sociobiology of sex in many literary characters. To that extent, the sociobiology of sex tells us what we already knew, but it makes it clearer and blunter, and at the same time subtler; it cuts through obfuscating piety and political correctness; and it dispels a cloud of relativistic doubts.

The purpose of this chapter, then, is to explain the consensus in the the sociobiology of sex. I am not a sociobiologist myself, but it is a compliment to sociobiology to say that at this point that is not too serious a handicap. The sociobiology of sex has succeeded to the extent that it no longer needs to be the sheltered conversation of specialists. It has begun to be popularized in books like Matt Ridley’s The Red Queen and Robert Wright’s The Moral Animal, and I think it deserves to be incorporated into the body of what every educated person should know, like the supply-and-demand chart in economics. Yet it also resembles supply and demand in that, to understand it, one has to think in a new and, we may say, disturbingly cynical way. One has to simplify, even in a sense to falsify, one’s view of the world, in order to adapt to a certain style of reasoning. This done, much becomes clear quite quickly, but building interpretive bridges back to a more complex reality can be difficult at times, and the ease of the method of reasoning tempts one to engage in sweeping, over-confident speculations. For a few basics, though, the logic is so impeccable and the weight of evidence so great that confidence almost to the point of certainty is warranted. I focus here on those basics.

Let me begin, then, with the idea of the “selfish gene,” pioneered by Richard Dawkins in his 1976 book of that name. One scandalous suggestion that once seemed to arise from Darwin's theory of evolution is that organisms, including people, must be completely selfish, because organisms that behaved altruistically, sacrificing themselves for the benefit of others, would contribute less to the next generation, and would be bred out of the population. Of course, much apparent altruism is observed among people, and to a lesser extent other organisms as well. That might seem to prove the theory of evolution false. But it turns out that there are several evolutionary explanations of altruism. First, evolution predicts a natural altruism towards kin. If the Darwinian imperative is for each organism to reproduce itself, the survival of its children should be almost as important to each as its own survival. More subtly, other kin, such as siblings, nieces and nephews, parents, cousins, etc., share some of its genes. So an organism with an instinct to protect its kin, if the cost is not too exorbitant, may be said to contribute disproportionally to the next generation in a sort of indirect fashion. But that is not the clearest way of putting it.

Dawkins' great insight was that it’s a mistake to focus on the organism at all. The real evolutionary competition is not between organisms but between genes. Organisms may be altruistic, because in evolutionary terms, they are mere vehicles for genes. A gene is present in many organisms, and it may be strategically smart to sacrifice one or more of these organisms for the benefit of others. And so organisms feel instinctive pressure to be altruistic or “moral,” but the genes are selfish.

There are other kinds of altruism, too, which serve the selfish genes' interests. Reciprocity-- I scratch your back, you scratch mine-- can help organisms flourish, so the selfish genes give us instincts such as gratitude and pity to facilitate that. Gratitude is altruism towards those who have helped you in the past. It is useful because potential benefactors may detect it, and be more inclined to help in one's time of need. Pity is altruism towards those who most desperately need it. It is useful because the desperate may be particularly grateful, if they flourish later, for the assistance that saved them in their darkest hour. Pity is a way to buy gratitude cheap. Again, one might behave "altruistically" to advertise to potential mates the superior fitness by which you acquire extra resources to give away. (Early in Tolstoy's Anna Karenina, Vronsky gives generously to the family of a railway worker who has just been killed, making by accident or design a favorable impression on Anna, whom he later seduces.) If any of these motives were present in the conscious mind, we should hardly call the act altruistic at all. But the point is that we are equipped with certain good instincts by the selfish genes, experienced by us as feelings urging us to help others, but more fundamentally explained by the selfish genes' strategies to help themselves.

It is almost inevitable that one begins to talk about the selfish genes as if they were conscious beings with will and reason, pursuing plans of their own. Of course, genes are not conscious, but a kind of quasi-intentionality arises from the fact that only genes which influence the organisms that carry them to behave in certain ways will survive in the long run, so surviving genes have to be pretty good at inducing these behaviors. A form of telos, a form of purposive behavior, thus emerges. Moreover, because evolution is a gradual process, the selfish genes are trapped in a time warp. Evolutionary honing of the human organism to its environment is a slow process, and that is the only way the selfish genes learn. They do not know (“know” is used metaphorically here) about contraception and sperm banks. They do not know about Christian monogamy. They probably do not know that we know that sex causes children. It is an interesting question whether they even know that we have the power of verbal communication. Probably they do not exactly know about marriage, but they do know a lot about permanent versus temporary mating, and they have written most of the script for marriage, with culture, as it were, writing the last chapter. They feed us feelings, urges, and impulses that would maximize our success in propagating them in some former environment where evolutionary honing had more time to play out, perhaps in a society of foraging bands.

Now for the crucial point. To the selfish genes, it is of great strategic importance whether an organism is male or female. It is important because the reproductive possibilities facing the two sexes are very different. For females, bearing a child is costly. It takes nine months of pregnancy and probably breast-feeding after that. Females cannot bear children more frequently than about once every year or two. For males, begetting a child is ridiculously cheap. It takes maybe an hour. Males can beget enormous numbers of children if they can secure access to enough females. In short: wombs are scarce, semen is abundant.

As a result, in seeking mates, males (are programmed by their selfish genes to) want quantity, females want quality. For males, there is a huge genetic payoff to mating prolifically. For females, there is not, because they cannot accelerate childbearing much anyway. Males will generally do whatever it takes to get a lot of sex. As long as it is just a one-night stand, it does not really matter how unpromising the girl is. If he can get her pregnant, even if the child has low odds of surviving and prospering, he has a shot at improving his selfish genes’ market share in the next generation. Females have reason to be choosier. If they accept a low-quality mate, they will be tied up for a year or more producing a child who is unlikely to survive and prosper. A high-quality mate might, in the best case, yield a son who will be a harem master in the next generation, winning the genetic sweepstakes. Males are eager, females coy.

So far, the theory’s predictions appear to be very accurate. Studies continually confirm the obvious: that yes, men are pretty eager to have sex at every opportunity, when not constrained by religious or marital scruples; and yes, females are not usually interested in casual sex, but are more interested in getting to know a man’s character and in establishing a committed relationship first. One obvious bit of data supporting the theory is that most prostitutes everywhere are female. There are far more men than women who want casual sex, and a prostitute's price reflects this imbalance in demand. Male prostitutes would face the difficulty, not only that women rarely want to get laid no-strings-attached, but if one did, she could (unless quite old or ugly) proposition the first man she sees on the street and have pretty good odds of success. Similar patterns are observed across cultures. Details vary, but the eager males, coy females rule applies to most other animal species as well.

Now for the second major principle: humans are a species characterized by high male parental investment. Male parental investment varies a lot among animal species, with the males of some species playing almost as large a role in parenting as the females do, or in rare cases even a larger role, while in others they do nothing except inseminate. High male parental investment is roughly the technical term for good family values, with dad earning a living to put food on the table for mom and the kids. But does that contradict what I said a moment ago about males being eager for sex at every opportunity? Well, sort of, and that is where things get interesting.

In a species where male parental investment is (a) important to raising young successfully, and (b) widely available, females will look for signals, in any potential mate, that he is willing to provide it. And males will sometimes be willing to provide it, since they can benefit by increasing the chances that their offspring will survive and prosper in the next generation. On the other hand, if a man gets a woman pregnant and abandons her, the child might survive anyway, and he is free to move on to other opportunities.

So each man faces a strategic dilemma: whether to be a “dad,” staying to guide and guard the children he has begotten by one or more women, or a “cad,” serially seducing and abandoning women. “Dad” types should still be on the lookout for opportunities to score on the side, in ways that do not disrupt the family too much, and they may desert wives who become reproductively unpromising. Always bear in mind that this is a prediction about human instincts, fundamental and precultural tendencies in behavior, which culture may express, modify, or suppress. In fact, we do see a lot of men behaving like dads and others behaving like cads. The theory is confirmed at that level. But the impulses men feel constitute a source of evidence, too, even when men do not act on them. Men have impulses to cherish and protect a loving and faithful wife, and to cherish, protect and teach their own children. On the other hand, men have a tendency to fixate on and fantasize about a certain kind of scantily clad woman, sometimes voluntarily and for fun, sometimes involuntarily as a temptation with which one wrestles unsuccessfully. I will take the liberty of suggesting that every man knows there is a dad and a cad in him, either of which he might choose to be, depending on circumstances and conscience.

In women, sociobiology stresses “the Madonna-whore dichotomy.” This tends to be a description of men’s perceptions rather than women’s strategic choices, though of course the two are related. Since men are eager for sex and women are coy, women have bargaining power, which they can use in different ways. They can try to discern a man’s inclination for parental investment, and be sexually reserved until he has proven to their satisfaction that he intends to provide it. The Madonna strategy. Or, they can extract resources up-front, asking for gifts in return for sex. The whore strategy.

For a man, or more precisely for his selfish genes, it is important to know what kind of woman he is dealing with, since if a woman is sexually promiscuous, staying to raise children with her is likely to result in his resources being invested in another man’s offspring, his worst-case scenario. So while men will look for easy women when they just want to have a little fun, they will value chastity in women they want to marry. A woman’s kin also have a stake in her reproductive success, and they may place great value on her chastity. There is a joke that “a social conservative is a liberal with a teenage daughter.” Fathers and brothers feel a natural impulse to protect a woman’s virginity, and to avenge it if it is violated.

Perhaps it seems appropriate to pair the dads with the Madonnas and the cads with the whores. But these types are often changeable and anyway not readily observable. Thus, a man might court a woman, trying to discern her character, and marry her if he is satisfied with her chastity and other desirable qualities, acting like a dad. But, if she turns out to be readier to have sex than he thought, he should, from his selfish genes’ perspective, play the cad, seducing her, then abandoning her, since she seems to be an easy lay, and not someone to be trusted as a wife. He might even tempt her sexually, in order to test her virtue, then, if she passes the test by refusing, classify her as a Madonna and offer to marry her, but if she yields, classify her as a whore and abandon her. This treacherous strategy is neatly expressed in a song sung by Ophelia in Shakespeare’s Hamlet:

Tomorrow is St. Valentine's day

All in the morning betime

And I a maid at your window

To be your Valentine.

Then up he rose and donn'd his clothes

and dupp'd the chamber door;

Let in the maid, that out a maid

Never departed more.

Quoth she, "Before you tumbled me,

You promis'd me to wed."

He answers:

"So would I ha'done, by yonder sun,

An [if] thou hadst not come to my bed."

The man in the song states his strategy with brutal directness. It might be more typical of a man to be less blunt, and cover himself with self-justifying excuses of one sort or another. But, more subtly, he might not be aware that he was testing her. Maybe from his point of view, he was ardently in love with her, and then, mysteriously, he was not. This emotional inconsistency serves him well, or rather, serves his selfish genes well, since he impregnated the girl but kept himself free. He was full of wild dreams of marriage, so he made his promise, and she, moved by it, gives herself to him. Then, afterwards, the idea of marrying her seems dull, claustrophobic, even a little horrible, and he hastens to make his escape. With his selfish genes pulling his emotional strings in this opportunistic fashion, he never, exactly, has to lie.

Meanwhile, women have their own treacherous strategies. A relatively mild form of exploitation is that they might lead a man on, raising his sexual hopes and inspiring him to spontaneous lovesick generosity, then deserting him. Much worse, wives might cheat on their husbands, secretly committing adultery with mates who seem to offer a better genetic contribution, while still enjoying parental investment by the deceived husband. DNA tests now make it possible, in principle, to estimate what we might call the “cuckoldry rate,” the proportion of children not begotten by the father of record. Cuckoldry is rare, probably less than 10% in most populations, but not negligible, and of course that comparatively low rate reflects not just the natural sexual fidelity of women, but also the success of men’s cuckoldry prevention strategies, instinctive and cultural, as well as women’s moral choices not to act on adulterous impulses. The crushes on movie stars which women often develop seem like an example of such impulses.

With men and women both having an incentive to deceive, a kind of arms race ensues, in which each gender hones its ability to deceive the other, and also to detect deceit by the other. Since men are looking for chastity, women learn to signal it, or to simulate it. Since women are looking for commitment, men learn to signal, or simulate, that. Men, in turn, learn to detect false signals of chastity, and women, false signals of commitment, and so on.

Much of this signalling goes on below the level of conscious thought and/or verbal communication. A man might be less attracted to older women because he consciously desires children, and knows that older women are less likely to be fertile. But even if he does not want children at the conscious level, his selfish genes do, and they will make him aesthetically prefer younger women. Sexual strategies rooted in the selfish genes may be adopted by the mind as conscious goals and rationally pursued with the cunning of a Casanova or a Scarlett O’Hara, or we may be the blind pawns of desires rooted in the selfish genes, or we may fight against and largely overcome those desires.

This much, at any rate, is clear: for a person to live so as to maximize the success of his selfish genes would be so horrible and crazy that it seems safe to assert that virtually no one does it. For a man, the genetically best strategy might be to be a serial rapist of Catholic schoolgirls who do not believe in abortion. He would end up in jail sooner or later but meanwhile might sire more offspring than even the most fortunate paterfamilias. That such a life would be not only hideously evil but also totally unhappy, wretched, and miserable does not matter to the selfish genes. But they do not know about Catholic opposition to abortion. They do not know that modern justice restricts punishment to the individual perpetrator and spares his family, nor do they know about the anonymity and abundance of potential victims modern society affords. The selfish genes are stuck in the Stone Age and anyway only feed us emotions and impulses, so they cannot tempt men to such a ruthless and rational (in the special sense of seeking the most effective means to a given end) pursuit of genetic interests. That said, the lives of history's kings and emperors often conform rather closely to the interests of their selfish genes, as they tend, except under the influence of Christianity, to acquire huge harems, using power to become fathers on a huge scale.

Again, in a way, we always knew, without help from sociobiology, that men want quantity, women quality, and both sexes often deceive the other and also jealously seek to detect deceit. These are old truths, long embedded in songs and stories, in poetry and proverbs, in plays and novels. But in the 20th century, psychoanalysis, feminism, moral relativism, and other new trends in thought cast doubt on them, and made them seem culturally contingent and arbitrary, or even pathological, and the air was full of vague dreams that a new, more sexually liberated world was just around the corner, in which all the “taboos” surrounding sex would suddenly pass away. Sociobiology provides a firm theoretical structure, around which evidence is steadily coalescing-- for much more of that, see the books cited above-- which shows why men and women are different, why men are eager and women coy, why there is a sexual double standard that values female chastity highly, but not male chastity, why it is men who propose marriage and men who hire prostitutes, why male jealousy focuses on the sexual act while female jealousy worries more about emotional attachments, why we “fall in love” and why it feels so nice to do so, but also, why there are cheaters and heartbreakers and why they cause so much suffering. There is more to human nature, and doubtless more even to human sexuality, than the selfish genes. Culture and free will can modify and override some of our instinctive impulses. But not without limit, and the selfish genes will keep trying to reassert themselves.

Now, one factor limiting the influence of these ideas about sex and the selfish genes is that they tend to be advocated in combination with evolution as a comprehensive theory of the origins of life, and often prefaced with arrogant dismissals of alternative cosmologies. Thus Matt Ridley writes that “to those who believe that the world was made in seven days by a man with a long beard and that therefore human nature cannot have been designed by selection but by an Intelligence, I merely bid a respectful good day. We have little common ground on which to argue because I share few of your assumptions.” Thus he writes off half his potential audience. He thinks he has to, because to a believer in intelligent design, his argument won’t make any sense. But there he is mistaken.

As I explained in Chapter 3, even if God made the world 6,000 years ago, He seems to have made it in ecological equilibrium, and from that fact, much can be deduced. Natural selection is a force that would tend to destabilize the ecological make-up of the world, unless the world is already in a fine-tuned ecological equilibrium. Otherwise, evolutionary competition within the gene pool would constantly tend to alter the composition of the gene pool. This provides a warrant for us to use arguments from the selfish genes as arguments from equilibrium, without needing to assume any particular narrative about the origins of all life on earth. For example, men are attracted to younger women because younger women are more likely to be virgin and fertile, and that makes attraction to younger women a good strategy for a man’s selfish genes. If a man had a genetic predisposition to like older widows, he might succeed in marrying or seducing some, but they would be unlikely to bear him any children, so this genetic predisposition of his would not be passed on to offspring and would disappear from the gene pool. We could postulate, if we liked, that formerly men’s age preferences were more diverse, and they had no particular tendency to prefer younger women, but the preference for younger women was more conducive to reproductive success and so came to dominate the gene pool. Or we could postulate that men have always had a preference for younger women, since humans evolved as a species, or since they were created by God. Evidence can be brought in at this point, but the theory does not depend on it: however the equilibrium came about, evolutionary logic shows why it can persist. Arguments from the selfish genes are not infallible, even if they are logically correct deductions from evolutionary competition in a given environment. There may be useful adaptations which the genes have not discovered, or the gene pool may in some respects be in a state of long-term disequilibrium. But evolutionary logic is a reasonable guide about what to expect, and helps to interpret the facts when they appear-- even for those who, like myself, agree with Thomas Nagel (2012) that “the materialist neo-Darwinist conception of nature is almost certainly false.”

Another example of an argument from equilibrium that can shed light on human sexuality is the comparison of testes size among primates. When women have sex with multiple partners, a man’s genetic success may depend on his sperm simply outnumbering those of his competitors. That has two interesting implications. First, if a man has reason to think someone else might be inseminating his mate, it is worth injecting more semen. Men adapted to inject more semen when they have been away from their mates for most of the day, than they do when they have been constantly with her, should win the “sperm competition” more often, and enjoy greater genetic success, so that this trait should spread. In fact, studies have shown that men do ejaculate more abundantly when they have been apart from a woman for a while. Second, the frequency of female adultery should, in ecological equilibrium, determine testes size. Large testes are a waste of resources if females are loyal, but become more important as female promiscuity increases. This pattern holds for our primate relatives: male gorillas and gibbons, whose females basically never stray, have small testes, while male chimpanzees and bonobos, whose females are promiscuous, have large testes. Human testes are somewhere in between, implying that in the environment of evolutionary adaptation, human females were more faithful than chimpanzees and bonobos, but more promiscuous than gorillas and gibbons, a prediction that paternity statistics and anthropological evidence seem to bear out. Now, to an evolutionist, male testes size represents a genetic record of the many thousands of years of female behavior that conditioned it, and the fact that evolutionary theory can make such a subtle prediction will increase his confidence in evolution. But a creationist can make the same argument without the backstory. However ecological equilibrium came about, by billions of years of evolution or by ex nihilo creation 6,000 years ago, it requires male anatomy to be well-honed for success in an ongoing genetic competition, and that requires testes to be the right size, not inconveniently large, but big enough to win sperm competitions sometimes.

To sum up what has been established so far, however life on earth and mankind in particular came into existence, mankind is, or was until recently, in a state of ecological equilibrium, and human nature must have certain traits for that equilibrium to be sustainable. We must, whatever else we are, be vehicles for the propagation of our selfish genes. Even the most reductionistic evolutionary theory need not imply that individuals are selfish: instinctive altruism can be motivated, for starters, by kin selection or hopes of reciprocity. Individuals may be genetically programmed for altruism because they are not the most fundamental propagating units. Genes are. Each gene is at work in thousands of different bodies at a given time, and genes are immortal and therefore ruthlessly selfish, else they would long since have lost market share in the gene pool. Our instincts, including generous ones, arise from the selfish genes pursuing their interests. The selfish genes do not tell us much about human nature that human tradition did not already know, but they do serve as a useful corrective to any excessively loose, free-wheeling, liberated and ultimately contentless view of human nature. Granted, human nature is wonderfully adaptable and creative. To almost any claim that might be made about it, some counter-example could be offered. An exploration of human nature which stood ready to abandon any claim in the face of a few counter-examples (emulating Karl Popper's vision of science, say) would get nowhere. One might end up thinking, as many (e.g. Sartre) seem to have done in the last century, that human nature has no central tendency at all, that nothing is typical or normal, that there is no human telos, no peculiar human flourishing, no good life for man, but only endless cross-currents of cultural influence in arbitrary flux, playing out meaninglessly across the pages of history. This ultimate skepticism about human nature finds expression in the uncritical and indignant rejection of “stereotypes” which is fashionable today. Against this skepticism, the selfish genes are an antidote.

In particular, the selfish genes make clear why there is a built-in differentiation and complementarity between the sexes, and also abundant incentives for deceit and exploitation. Men seek quantity of mates, have an innate aspiration to polygamy, like opportunistic one-night stands and may pay for more them explicitly or implicitly, and are jealous principally of women's sexual fidelity.Other men's wives, promiscuous women, and virgins are all worth a seduction if he can manage it, though men also have paternal instincts and will sometimes invest in their offspring. Women seek quality in mates, have no innate preference for polyandry, do not usually like one-night stands unless the mate seems to have exceptionally high quality genes, but may offer sex to men in exchange for resources, and are jealous of a mate's emotional devotion to herself as a proxy for his likely physical investment in joint offspring. A man's selfish genes' worst-case scenario is that a man is cuckolded, exploited to raise the offspring of another man, so they make him value virginity in a bride and fidelity in a wife, and feel murderous rage at a wife's lover and hatred and disgust towards an unfaithful wife. Neither men nor women are typically aware of these calculations, which affect them as spontaneous emotions of delight, admiration, anger or disgust. Indeed, if I were writing this to a non-human audience, I would almost despair of explaining how the same act could be in one sense the work of the selfish genes and in another of the conscious will, but we know what it is like. All humans have had the experience of feeling desires and at the same time resisting them. The selfish genes do not tell us why we have souls that can perceive right and wrong and choose between them, but they shed plenty of light on the nature of our sexual desires, both legitimate ones which we rightly pursue, and evil ones which we struggle against as temptations.

Now, while there is more to marriage than the selfish genes, marriage cannot be understood apart from the selfish genes and their peculiar, pervasive, and decidedly asymmetric influence on what men and women want from each other. Marriage could, in principle, take an infinite variety of forms. Why not have a marriage between seven men and seven women, who rotate sexual partners according to the days of the week? Why not have a marriage in which adultery is forbidden on weekdays but allowed on weekends? Because men’s instincts compel them to insist on the sexual fidelity of their mates. Why not have a marriage which lasts twelve months and then automatically expires unless both spouses wish to renew it? Primarily because women’s instincts drive them to insist on permanence, as a proxy for male parental investment.  

The symmetry of modern marriage is misleading. From the selfish genes’ point of view, male and female adultery are different evils. Male adultery, or even infatuation, is a diversion of resources from the parental investment and may precipitate abandonment. Female adultery threatens a man with cuckoldry and provokes violent jealousy. In the past, wives of successful men have often tolerated their husbands’ philandering, while men fought duels with their wives’ lovers. Modern marriage, following a pattern pioneered by Christianity, prohibits both male and female adultery, and thus manages to be pleasingly symmetric and consensual, while still appeasing the selfish genes at least to some extent, though monogamy requires its participants to be ready to resist sexual temptation, too. But many other arrangements, such as the weekday-rotation-among-partners and adultery-on-weekends-only variations on marriage suggested above, would be symmetric and consensual, but are vetoed by the selfish genes of either men or women. In any case, modern marriage is not perfectly symmetric. It is still much commoner for men to be breadwinners, women homemakers, than the other way around. Men almost always propose marriage. Husbands are usually older than wives. Remembering anniversaries and giving flowers are things wives expect of husbands, not the other way around.

Meanwhile, what do the selfish genes have to say about homosexuality? The most obvious point is that homosexual orientation is diametrically opposed to the selfish genes’ interests. One might therefore conclude that homosexuality cannot be a natural phenomenon, that is, a phenomenon that would occur in the environment of evolutionary adaptation, but must arise somehow from the influences of culture or civilized humanity’s general maladaptation to the environment we have created for ourselves. But this conclusion is too hasty. Homosexuals seem to prefer to regard their sexual orientation as genetically based, and E.O. Wilson explains how this could make sense:

Committed homosexuality, with the preference appearing in childhood, is heritable. This means the trait is not always fixed, but part of the greater likelihood of a person’s developing into a homosexual is prescribed by genes that differ from those that lead to heterosexuality. It has further turned out that heredity-influenced homosexuality occurs in populations worldwide too frequently to be due to mutations alone. Population geneticists use a rule of thumb to account for abundance at this level: if a trait cannot be due solely to random mutations, and yet it lowers or eliminates reproduction in those who have it, then the trait must be favored by natural selection working on a target of some other kind. For example, a low dose of homosexual-tending genes may give competitive advantages to a practicing heterosexual. Or, homosexuality may give advantages to the group by special talents, unusual qualities of personality, and the specialized roles and professions it generates. There is abundant evidence that such is the case in both preliterate and modern societies. (E.O. Wilson, The Social Conquest of the Earth)

Wilson’s last claim of “abundant evidence” sounds like bluff-- when Wilson has real evidence for a claim, he is perfectly capable of explaining what it is-- but it is logically possible that homosexuality is genetically based, and the superficial puzzle of homosexual orientation is explained by genetic advantages that accrue to individuals with low doses of heterosexual genes, or to homosexuals’ kin. The evidence suggests, however, that genes are not the whole story. When testing whether a trait is genetically based or not, the scientific gold standard is to study identical twins who were separated at birth, since identical twins by definition have exactly the same genes. With the same genes, but different environments, identical twins provide the perfect data to test the part that “nature”-- genes-- and “nurture”-- environment, culture, religion, upbringing, etc.-- play in shaping a person’s behavior, character, tastes, talents, and so on. Twin studies show that when one identical twin is homosexual, the other is usually heterosexual, but is more likely to be homosexual than someone randomly chosen from the population. It seems, then, that homosexual orientation is influenced but not determined by the genes. Moreover, some fluidity in homosexual vs. heterosexual orientation over time has been observed, contradicting the idea that all homosexuality is rigidly prescribed by the genes. At any rate, logic and evidence to date do not supply us with any strong genetically-based explanation of homosexual orientation.

But even if we do not know why homosexuality occurs, the selfish genes still shed light on homosexuals’ behavior, simply because gay men are men, and lesbian women are women. Thus, Matt Ridley offers the following explanation of the observed promiscuity of gay men:

If the existence of female prostitutes reveals the male sexual appetite in its nakedness, then so, too, does the phenomenon of male homosexuality. Before the advent of AIDS, practicing male homosexuals were far more promiscuous than heterosexual men. Many gay bars were, and are, recognized places for picking up partners for one-night stands. The bathhouses of San Francisco catered to orgies and feats of repeated sex, assisted by stimulants, that boggled the mind when publicly discussed during the early years of the AIDS epidemic. A Kinsey Institute study of gay men in the San Francisco Bay area found that 75 percent had had more than one hundred partners; 25 percent had had more than one thousand... Activists would say that homosexual promiscuity is caused largely by society’s disapproval. Illegitimate, “shameful” activities tend to be indulged in to excess when indulged at all. The legal and social difficulty of forming gay “marriages” mitigates against stable relationships.

But this is not persuasive. Promiscuity is not confined to those who indulge in gay sex clandestinely. Infidelity is acknowledged to be a greater problem in male gay “marriages” than in heterosexual ones, and society’s disapproval is far greater of casual than of stable homosexual relations. Many of the same arguments apply to lesbians, who show a striking contrast: Lesbians rarely tend to indulge in sex with strangers but instead form partnerships that persist for many years with little risk of infidelity. Most lesbians have fewer than ten partners in their lifetimes... The reason male homosexuals on average have more sexual partners than male heterosexuals, and many more than female homosexuals, [seems to be] that male homosexuals are acting out male tendencies or instincts unfettered by those of women... Homosexual men behave like men, only more so. (Ridley, The Red Queen)

Culture makes marriage, if you like, but it does not make it ex nihilo. It works with the raw material of human instinct, of asymmetric desires and generosities and jealousies. Marriage goes against the grain of human nature in important respects, and fierce enforcement of marital rules is sometimes needed, whether that function is fulfilled by government, public opinion, religious instruction, or vengeful fathers and brothers, but much of the behavioral content of a happy marriage arises from the selfish genes. "Married" gay couples may imitate straight married couples in a given cultural context, especially in the short run, but fundamentally there is no reason to expect gay relationships to have the same behavioral content as marriage, even if the law prescribes that they be called marriages. As an example of this problem, some worry that gay men in particular would set a bad example by continuing within marriage the promiscuity that has been common among gay men outside it, acting out the greater propensity for promiscuity which is characteristic of men by nature, but of which the less promiscuous nature of women tends to deprive straight men of the opportunity. Gay marriage advocates Jonathan Rauch and Andrew Sullivan have basically admitted that this is probable. The selfish genes ensure that “adultery is allowed on weekends” or “swap partners each night of the week” will never be the normal rules for straight marriage, but they could, for all the selfish genes have to say about it, become normal for gays.

Appendix 1: Evolution and the Magic Rat Parable

While I have stressed that belief or disbelief in evolution is not essential to the argument, I will probably have provoked some curiosity as to whether I, personally, do believe in evolution. In fact, I am an evolution skeptic. Partly, this is for philosophical reasons. The theory of evolution seems to reduce people to animals, animals to biochemistry, and in general, everything to a material basis. It brings the materialist worldview, which emerged as a kind of extrapolation from the methodological presumptions of the natural sciences, to a point of completeness and comprehensiveness, so that it can serve as a picture of total reality. Matter, energy, time, and space are all that there is. 

But it seems clear to me that that is not true. There are non-material entities, starting with numbers, which have an existence quite independent of the space-time continuum. Heaven and earth shall pass away, but not one jot nor tittle shall pass away from the multiplication table. Ideas, while they don’t seem as obviously independent of the material universe as numbers are, seem equally to elude reduction to matter. The same idea may be present in your mind, mine, and many others far removed in space and time. Since our minds seem to have some connection with our brains, yet they are also able to make contact with these non-material entities, it seems most realistic to regard ourselves, as C.S. Lewis put it, as “amphibians,” capable of inhabiting and moving back and forth between two worlds, the material world and a world of ideas. About the latter much more could be said, but this is sufficient to rule out materialism, and therefore to rule out merely materialistic evolution.

The theory of evolution, and the scientific materialist worldview of which it is the capstone, also implies that everything, including our minds, is governed by deterministic or random natural laws, but our behavior is not deterministic or random. We know by introspection, a source of knowledge more epistemically fundamental than any conclusions of science even if it what it teaches us is often difficult to articulate, that we have free will. Scientific materialism rules out free will, therefore it cannot be wholly correct.

Even if we set aside these philosophical questions and examine the theory of evolution from a more purely scientific standpoint, we don’t know whether the mechanisms that Darwinian natural selection and Mendelian genetics elucidate are sufficiently powerful to explain the emergence of life in its observed complexity. As this is a very subtle point, I offer the following parable to help readers understand it.

Goodman Industries has been preparing its bid for a major government contract for several years, when suddenly, just before they deliver their proposal, their computer systems suffer a devastating hacker attack. Goodman fails to recover their data and is forced to withdraw its bid. It asks the FBI to investigate. After a few weeks of careful research, the FBI traces the attack to a boutique software company called Wily Whizzkids, whose eccentric boss has been nicknamed “the Magic Rat” because he has a legendary knack for tunneling his way through labyrinthine programming problems. Investigating further, the FBI learns that Wily Whizzkids just signed an extremely lucrative but rather vague contract with Rogue Industries, Goodman’s nemesis, and a rival bidder for the government contract that Goodman had been almost assured of getting prior to the hacker attack. This strong circumstantial evidence is enough for the FBI to initiate a case, and the Magic Rat is arrested.

He doesn’t seem very worried, however. He has a story. Wily Whizzkids, he explains, has been experimenting with a new method of programming known as “evolutionary computing.” Random algorithms are generated in a “tank,” then given computational problems to solve, which are taken from the work of Wily Whizzkids itself and other similar companies, from textbooks and from history, and whatever sources seem convenient. Algorithms that solve problems are given “food”-- runtime-- and sometimes are allowed to reproduce themselves, usually by “mitosis,” being simply copied, occasionally by “meiosis,” being spliced together with other algorithms that have had some success, and more rarely, with mutations that alter the code slightly. Algorithms can offer “food” on their own account to other algorithms that solve sub-problems, which leads to symbiosis and sometimes incorporation of different algorithms into larger programs that replicate together. While the vast majority of the randomly generated bits of code are worthless, this process of “natural selection” filters out the worthless code, and what survives and replicates are bits of code that can do real tasks.

The hope was that the evolutionary computing laboratory would generate new solutions to coding problems that had flummoxed their best engineers. The virus that attacked Goodman Industries was not designed by anyone, but emerged spontaneously from the evolutionary computing laboratory. Probably its targeting of Goodman was an unintended side-effect of Wily Whizzkids borrowing a lot of outstanding problems from Rogue Industries, with whom they happened to be in negotiations, to feed the laboratory, and some of those referenced Goodman because Rogue was researching competitors for the bid. The Magic Rat therefore admits to negligence in insufficiently insulating the laboratory from the general internet, and is ready to pay damages in a civil suit. But he denies any intentional wrongdoing. As for the Rogue Industries contract: yes, the Magic Rat negotiated hard, and expects it to be extremely profitable, but Rogue placed a high value on the project in question, and Wily Whizzkids has unique expertise which Rogue felt was essential to its success. Certainly, there was no quid pro quo that Wily Whizzkids had to arrange a virus attack on Goodman to secure a government contract for Rogue. That was just a coincidence.

The FBI investigates, and of course they find that Wily Whizzkids does have an evolutionary computing laboratory matching the Magic Rat’s description. They even find what seem like earlier versions of the Goodman virus in the laboratory. But of course, the Magic Rat might have set up the laboratory for plausible deniability’s sake, then designed the Goodman virus deliberately, along with plausible forerunners, and planted them in the laboratory. Goodman’s lawyers study the case and conclude unanimously that they have to nail the Rat on a criminal charge. The real scale of the damage done to Goodman by losing the contract, which was a major priority for the company for years and motivated many of its hires, much of its research, and one or two acquisitions of other companies, and whose value to Goodman lay less in its profitability per se than in the contacts, expertise, and reputation it would gain through the contract, is much larger than what they could hope to win back in a court settlement, and also than what the Magic Rat stands to make from his contract with Rogue. If the Magic Rat pays only civil damages, he and Rogue win. But if they can nail him on a criminal charge, they can go after not only Wily Whizzkids but Rogue, too, extract larger damages, and maybe even force Rogue to give up the government contract.

So Goodman starts contacting the world’s top experts in computer science, algorithm design, and math, hoping to find someone who can prove in court that the Magic Rat’s evolutionary computing laboratory couldn’t have designed the Goodman virus.

Consider the problem, then, of an expert witness working for Goodman. You have access to the laboratory and you know how it works. You know how long it’s been running. Your task is to somehow quantify the probability that it would generate a program as complex and effective as the Goodman virus in the time available. My guess is that if this could be done correctly, the Rat’s guilt or innocence would become quite obvious. The probability of something like the Goodman virus emerging would be either 99.999% or more, or 0.0001% or less. But to quantify the complexity and effectiveness of programs, and to measure the effectiveness of the laboratory in generating that complexity and effectiveness, would be a mind-boggling feat in the realms of information theory and the philosophy of probability, probably exceeding what anyone in the world can do. And even if the expert did come up with some method of quantifying the complexity and the power of the evolutionary mechanisms, so as to make at least an educated guess about the Rat’s guilt, would the expert, let alone the jury, really be able to be confident that his method was correct?

Now, in judging the plausibility of the theory of evolution, we are placed in a similar position to Goodman’s expert witness. The theory of evolution claims that all life on earth originated through processes of natural (including sexual) selection and mutation (or genetic drift), playing out over the course of a few billion years. Are these evolutionary mechanisms powerful enough to explain the complexity of life on earth as we observe it? How can we know? How can we quantify, on the one hand, the complexity of life and its designs, and on the other hand, the power of evolutionary mechanisms as designers, in order to check whether the latter is sufficient to explain the former? Here we are at a disadvantage relative to Goodman’s expert witnesses, for they at least might be able to rerun the laboratory from scratch and see how much complexity it generated in a given time, whereas we cannot rerun the Earth and see if it generates sentient life from primordial soup in a few billion years. It may be that if we could quantify life’s complexity and evolution’s power, we would find that the emergence of sentient life was a near certainty, or on the other hand, that it was prohibitively improbable.

The main evidence that evolution could generate the complexity of life on Earth seems to be that it did. Life is a fact. Science knows of no way but evolution in which it could have arisen. Therefore evolution must be powerful enough to explain life in all its variety and cunning and beauty. That is where the case of evolution differs from the case of the Magic Rat. In the case of the Magic Rat, there is nothing metaphysically problematic or unscientific about the hypothesis that the Goodman virus had, so to speak, an Intelligent Designer, namely the Magic Rat. But if life has an Intelligent Designer, the only candidate for the role would seem to be a supernatural God, and that is an entity which science avoids incorporating into its theories on principle. Still, when the only acceptable explanation one can think of for some observed fact may be impossible, one must not assume that it is possible merely because otherwise the fact remains unexplained.  

In supposing that evolution must be powerful enough to generate life on Earth because otherwise they cannot explain life on Earth, scientists are in a position like that of a little girl, who, unable to explain how water gets into the sky to fall as rain, assumes that there must be giant ladders into the clouds somewhere, with long rows of men in galoshes and yellow raincoats marching up them with buckets to dump water into sponge-like clouds. After all, she reasons, water must get up into the sky somehow, and she does not know about evaporation. The buckets and giant ladders are the only explanation she can think of, so it must be true.

My vague sense is that evolutionary mechanisms are quite insufficient to explain life on earth. That is worth very little, yet science cannot really prove me wrong. More importantly, I can recommend what I feel confident is the right policy here, namely, to be a skeptic, to refrain from holding any confident beliefs about the process by which life on earth arose. But enough of this digression.

Appendix 2: Evolutionary psychology and the Fall

This appendix is for Christian readers only. Evolutionary psychology represents human nature as, if not wholly evil, certainly full of evil urges and propensities. Can a good God have created us that way? Can it have been necessary for God to create us that way, in order to satisfy the requirements of ecological equilibrium, as my argument has perhaps suggested?

But the answer is clear: what evolutionary psychology elucidates is not human nature as God intended it, but fallen human nature. The doctrine of the Fall has always been central to Christianity, and some theologians, like Augustine of Hippo, have seen it at work in the facts of human physiology. Evolutionary psychology can be seen as providing a partial confirmation of this ancient view.

Nor is it necessary that human nature should have these traits, except in a special and limited sense. Given the way the world works now, subject to the law of entropy that things are always running down, with life having become competitive and often predatory, and with human beings, too, competing with and sometimes preying on each other, the selfish genes have their way with us. But the divine order before the Fall seems to have been quite different, and there was no need then for evil adaptations to an evil environment.

Rather than creating the world in ecological equilibrium as we observe it today, God may have created the world in a very different and better state, and human beings, who were appointed as caretakers of nature, might have maintained it in this better state, had they remained obedient to God. Without committing to any position on how historically accurate the early books of the Bible are or are not, it is interesting that the Bible suggests that man was not so much immediately as progressively corrupted after the Fall. Perhaps the selfish genes played a role in that process.