The Blank Slate: The Modern Denial of Human Nature

  Why do people’s intuitions go in opposite directions—both “If he has trouble controlling himself, he should be punished more leniently” and “If he has trouble controlling himself, he should be punished more severely”? It goes back to the deterrence paradox. Suppose some people need a threat of one lash with a wet noodle to deter them from parking in front of a fire hydrant. Suppose people with a bad gene, a bad brain, or a bad childhood need the threat of ten lashes. A policy that punishes illegal parkers with nine lashes will cause unnecessary suffering and not solve the problem: nine lashes is more than necessary to deter ordinary people and less than necessary to deter defective people. Only a penalty of ten lashes can reduce both illegal parking and lashing: everyone will be deterred, no one will block hydrants, and no one will get whipped. So, paradoxically, the two extreme policies (harsh punishment and no punishment) are defensible and the intermediate ones are not. Of course, people’s deterrence thresholds in real life aren’t pinned at just two values but are broadly distributed (one lash for some people, two for others, and so on), so many intermediate levels of punishment will be defensible, depending on how one weights the benefits of deterring wrongdoing against the costs of inflicting harm.

  Even for those who are completely undeterrable, because of frontal-lobe damage, genes for psychopathy, or any other putative cause, we do not have to allow lawyers to loose them on the rest of us. We already have a mechanism for those likely to harm themselves or others but who do not respond to the carrots and sticks of the criminal justice system: involuntary civil commitment, in which we trade off some guarantees of civil liberties against the security of being protected from likely predators. In all these decisions, the sciences of human nature can help estimate the distribution of deterrabilities, but they cannot weight the conflicting values of avoiding the greatest amount of unnecessary punishment and preventing the greatest amount of future wrongdoing.19

  I do not claim to have solved the problem of free will, only to have shown that we don’t need to solve it to preserve personal responsibility in the face of an increasing understanding of the causes of behavior. Nor do I argue that deterrence is the only way to encourage virtue, just that we should recognize it as the active ingredient that makes responsibility worth keeping. Most of all, I hope I have dispelled two fallacies that have allowed the sciences of human nature to sow unnecessary fear. The first fallacy is that biological explanations corrode responsibility in a way that environmental explanations do not. The second fallacy is that causal explanations (both biological and environmental) corrode responsibility in a way that a belief in an uncaused will or soul does not.

  Chapter 11

  The Fear of Nihilism

  THE FINAL FEAR of biological explanations of the mind is that they may strip our lives of meaning and purpose. If we are just machines that let our genes make copies of themselves, if our joys and satisfactions are just biochemical events that will someday sputter out for good, if life was not created for a higher purpose and directed toward a noble goal, then why go on living? Life as we treasure it would be sham, a Potemkin village with only a façade of value and worth.

  The fear comes in two versions, religious and secular. A sophisticated version of the religious concern was formulated by Pope John Paul II in a 1996 address to the Pontifical Academy of Sciences, “Truth Cannot Contradict Truth.”1 The Pope acknowledged that Darwins theory of evolution is “more than just a hypothesis,” because converging discoveries in many independent fields, “neither sought nor fabricated,” argue in its favor. But he drew the line at “the spiritual soul,” a transition in the evolution of humans that amounted to an “ontological leap” unobservable by science. The spirit could not have emerged “from the forces of living matter,” because that cannot “ground the dignity of the person”:

  Man is the only creature on earth that God has wanted for its own sake…. In other terms, the human individual cannot be subordinated as a pure means or a pure instrument, either to the species or to society; he has value per se. He is a person. With his intellect and his will, he is capable of forming a relationship of communion, solidarity and self-giving with his peers…. Man is called to enter into a relationship of knowledge and love with God himself, a relationship which will find its complete fulfillment beyond time, in eternity….

  It is by virtue of his spiritual soul that the whole person possesses such a dignity even in his body…. If the human body take its origin from pre-existent living matter, the spiritual soul is immediately created by God…. Consequently, theories of evolution which, in accordance with the philosophies inspiring them, consider the spirit as emerging from the forces of living matter or as a mere epiphenomenon of this matter, are incompatible with the truth about man. Nor are they able to ground the dignity of the person.

  In other words, if scientists are right that the mind emerged from living matter, we would have to give up the value and dignity of the individual, solidarity and selflessness with regard to our fellow humans, and the higher purpose of realizing these values through the love of God and knowledge of his plans. Nothing would keep us from a life of callous exploitation and cynical self-centeredness.

  Needless to say, debating the Pope is the ultimate exercise in futility. The point of this section is not to refute his doctrines, nor is it to condemn religion or argue against the existence of God. Religions have provided comfort, community, and moral guidance to countless people, and some biologists argue that a sophisticated deism, toward which many religions are evolving, can be made compatible with an evolutionary understanding of the mind and human nature.2 My goal is defensive: to refute the accusation that a materialistic view of the mind is inherently amoral and that religious conceptions are to be favored because they are inherently more humane.

  Even the most atheistic scientists do not, of course, advocate a callous amorality. The brain may be a physical system made of ordinary matter, but that matter is organized in such a way as to give rise to a sentient organism with a capacity to feel pleasure and pain. And that in turn sets the stage for the emergence of morality. The reason is succinctly explained in the comic strip Calvin and Hobbes (see p. 188).

  The feline Hobbes, like his human namesake, has shown why an amoral egoist is in an untenable position. He is better off if he never gets shoved into the mud, but he can hardly demand that others refrain from shoving him if he himself is not willing to forgo shoving others. And since one is better off not shoving and not getting shoved than shoving and getting shoved, it pays to insist on a moral code, even if the price is adhering to it oneself. As moral philosophers through the ages have pointed out, a philosophy of living based on “Not everyone, just me!” falls apart as soon as one sees oneself from an objective standpoint as a person just like others. It is like insisting that “here,” the point in space one happens to be occupying at the moment, is a special place in the universe.3

  The dynamic between Calvin and Hobbes (the cartoon characters) is inherent to social organisms, and there are reasons to believe that the solution

  Calvin and Hobbes © Watterson. Reprinted with permission of Universal Press Syndicate.

  All rights reserved.

  to it—a moral sense—evolved in our species rather than having to be deduced from scratch by each of us after we’ve picked ourselves up out of the mud.4 Children as young as a year and a half spontaneously give toys, proffer help, and try to comfort adults or other children who are visibly distressed.5 People in all cultures distinguish right from wrong, have a sense of fairness, help one another, impose rights and obligations, believe that wrongs should be redressed, and proscribe rape, murder, and some kinds of violence.6 These normal sentiments are conspicuous by their absence in the aberrant individuals we call psychopaths.7 The alternative, then, to the religious theory of the source of values is that evolution endowed us with a moral sense, and we have expanded its circle of application over the course of history through reason (grasping the logical interchangeability of our inter
ests and others’), knowledge (learning of the advantages of cooperation over the long term), and sympathy (having experiences that allow us to feel other people’s pain).

  How can we tell which theory is preferable? A thought experiment can pit them against each other. What would be the right thing to do if God had commanded people to be selfish and cruel rather than generous and kind? Those who root their values in religion would have to say that we ought to be selfish and cruel. Those who appeal to a moral sense would say that we ought to reject God’s command. This shows—I hope—that it is our moral sense that deserves priority.8

  This thought experiment is not just a logical brainteaser of the kind beloved by thirteen-year-old atheists, such as why God cares how we behave if he can see the future and already knows. The history of religion shows that God has commanded people to do all manner of selfish and cruel acts: massacre Midianites and abduct their women, stone prostitutes, execute homosexuals, burn witches, slay heretics and infidels, throw Protestants out of windows, withhold medicine from dying children, shoot up abortion clinics, hunt down Salman Rushdie, blow themselves up in marketplaces, and crash airplanes into skyscrapers. Recall that even Hitler thought he was carrying out the will of God.9 The recurrence of evil acts committed in the name of God shows that they are not random perversions. An omnipotent authority that no one can see is a useful backer for malevolent leaders hoping to enlist holy warriors. And since unverifiable beliefs have to be passed along from parents and peers rather than discovered in the world, they differ from group to group and become divisive identity badges.

  And who says the doctrine of the soul is more humane than the understanding of the mind as a physical organ? I see no dignity in letting people die of hepatitis or be ravaged by Parkinson’s disease when a cure may lie in research on stem cells that religious movements seek to ban because it uses balls of cells that have made the “ontological leap” to “spiritual souls.” Sources of immense misery such as Alzheimer’s disease, major depression, and schizophrenia will be alleviated not by treating thought and emotion as manifestations of an immaterial soul but by treating them as manifestations of physiology and genetics.10

  Finally, the doctrine of a soul that outlives the body is anything but righteous, because it necessarily devalues the lives we live on this earth. When Susan Smith sent her two young sons to the bottom of a lake, she eased her conscience with the rationalization that “my children deserve to have the best, and now they will.” Allusions to a happy afterlife are typical in the final letters of parents who take their children’s lives before taking their own,11 and we have recently been reminded of how such beliefs embolden suicide bombers and kamikaze hijackers. This is why we should reject the argument that if people stopped believing in divine retribution they would do evil with impunity. Yes, if nonbelievers thought they could elude the legal system, the opprobrium of their communities, and their own consciences, they would not be deterred by the threat of spending eternity in hell. But they would also not be tempted to massacre thousands of people by the promise of spending eternity in heaven.

  Even the emotional comfort of a belief in an afterlife can go both ways. Would life lose its purpose if we ceased to exist when our brains die? On the contrary, nothing invests life with more meaning than the realization that every moment of sentience is a precious gift. How many fights have been averted, how many friendships renewed, how many hours not squandered, how many gestures of affection offered, because we sometimes remind ourselves that “life is short”?

  WHY DO secular thinkers fear that biology drains life of meaning? It is because biology seems to deflate the values we most cherish. If the reason we love our children is that a squirt of oxytocin in the brain compels us to protect our genetic investment, wouldn’t the nobility of parenthood be undermined and its sacrifices devalued? If sympathy, trust, and a yearning for justice evolved as a way to earn favors and deter cheaters, wouldn’t that imply that there are really no such things as altruism and justice for their own sake? We sneer at the philanthropist who profits from his donation because of the tax savings, the televangelist who thunders against sin but visits prostitutes, the politician who defends the downtrodden only when the cameras are rolling, and the sensitive new-age guy who backs feminism because it’s a good way to attract women. Evolutionary psychology seems to be saying that we are all such hypocrites, all the time.

  The fear that scientific knowledge undermines human values reminds me of the opening scene in Annie Hall, in which the young Alvy Singer has been taken to the family doctor:

  MOTHER: He’s been depressed. All of a sudden, he can’t do anything.

  DOCTOR: Why are you depressed, Alvy?

  MOTHER: Tell Dr. Flicker. [Answers for him.] It’s something he read.

  DOCTOR: Something he read, huh?

  ALVY: [Head down.] The universe is expanding.

  DOCTOR: The universe is expanding?

  ALVY: Well, the universe is everything, and if it’s expanding, someday it will break apart and that would be the end of everything!

  MOTHER: What is that your business? [To the doctor.] He stopped doing his homework.

  ALVY: What’s the point?

  The scene is funny because Alvy has confused two levels of analysis: the scale of billions of years with which we measure the universe, and the scale of decades, years, and days with which we measure our lives. As Alvy’s mother points out, “What has the universe got to do with it? You’re here in Brooklyn! Brooklyn is not expanding!”

  People who are depressed at the thought that all our motives are selfish are as confused as Alvy. They have mixed up ultimate causation (why something evolved by natural selection) with proximate causation (how the entity works here and now). The mix-up is natural because the two explanations can look so much alike.

  Richard Dawkins showed that a good way to understand the logic of natural selection is to imagine that genes are agents with selfish motives. No one should begrudge him the metaphor, but it contains a trap for the unwary. The genes have metaphorical motives—making copies of themselves—and the organisms they design have real motives. But they are not the same motives. Sometimes the most selfish thing a gene can do is wire unselfish motives into a human brain—heartfelt, unstinting, deep-in-the-marrow unselfishness. The love of children (who carry one’s genes into posterity), a faithful spouse (whose genetic fate is identical to one’s own), and friends and allies (who trust you if you’re trustworthy) can be bottomless and unimpeachable as far as we humans are concerned (proximate level), even if it is metaphorically self-serving as far as the genes are concerned (ultimate level).

  I suspect there is another reason why the explanations are so easily confused. We all know that people sometimes have ulterior motives. They may be publicly generous but privately greedy, publicly pious but privately cynical, publicly platonic but privately lusting. Freud accustomed us to the idea that ulterior motives are pervasive in behavior, exerting their effects from an inaccessible stratum of the mind. Combine this with the common misconception that the genes are a kind of essence or core of the person, and you get a mongrel of Dawkins and Freud: the idea that the metaphorical motives of the genes are the deep, unconscious, ulterior motives of the person. That is an error. Brooklyn is not expanding.

  Even people who can keep genes and people apart in their minds might find themselves depressed. Psychology has taught us that aspects of our experience may be figments, artifacts of how information is processed in the brain. The difference in kind between our experience of red and our experience of green does not mirror any difference in kind in lightwaves in the world—the wavelengths of light, which give rise to our perception of hue, form a smooth continuum. Red and green, perceived as qualitatively different properties, are constructs of the chemistry and circuitry of our nervous system. They could be absent in an organism with different photopigments or wiring; indeed, people with the most common form of colorblindness are just such organisms. And the emotional coloring of
an object is as much a figment as its physical coloring. The sweetness of fruit, the scariness of heights, and the vileness of carrion are fancies of a nervous system that evolved to react to those objects in adaptive ways.

  The sciences of human nature seem to imply that the same is true of right and wrong, merit and worthlessness, beauty and ugliness, holiness and baseness. They are neural constructs, movies we project onto the interior of our skulls, ways to tickle the pleasure centers of the brain, with no more reality than the difference between red and green. When Marley’s ghost asked Scrooge why he doubted his senses, he said, “Because a little thing affects them. A slight disorder of the stomach makes them cheats. You may be an undigested bit of beef, a blot of mustard, a crumb of cheese, a fragment of an underdone potato. There’s more of gravy than of grave about you, whatever you are!” Science seems to be saying that the same is true of everything we value.

  But just because our brains are prepared to think in certain ways, it does not follow that the objects of those thoughts are fictitious. Many of our faculties evolved to mesh with real entities in the world. Our perception of depth is the product of complicated circuitry in the brain, circuitry that is absent from other species. But that does not mean that there aren’t real trees and cliffs out there, or that the world is as flat as a pancake. And so it may be with more abstract entities. Humans, like many animals, appear to have an innate sense of number, which can be explained by the advantages of reasoning about numerosity during our evolutionary history. (For example, if three bears go into a cave and two come out, is it safe to enter?) But the mere fact that a number faculty evolved does not mean that numbers are hallucinations. According to the Platonist conception of number favored by many mathematicians and philosophers, entities such as numbers and shapes have an existence independent of minds. The number three is not invented out of whole cloth; it has real properties that can be discovered and explored. No rational creature equipped with circuitry to understand the concept “two” and the concept of addition could discover that two plus one equals anything other than three. That is why we expect similar bodies of mathematical results to emerge from different cultures or even different planets. If so, the number sense evolved to grasp abstract truths in the world that exist independently of the minds that grasp them.