Steven Pinker is a psychology professor. The book is about a theory of human behavior, but first he sets up the epistemology of the way we think about human behavior. The three laws he presents throw out much of what we believe, and in particular, the Tabula Rasa, the Blank Slate (empiricism) we think all humans are when they are born. Cold moms cause autism and schizophrenia is caused by double binds. Genes have nothing to do with it. While you may not believe this literal bold statement, you probably believe in some of the other theories which dominate the nature vs nurture debate

The other two important theories of behavior which Pinker debunks are the Noble Savage (romanticism) and the Ghost in the Machine (dualism). We are innocent babes, Noble Savages, who just need to be shown The Way. Society's structures are ill-formed to help keep us that way. Oh to be children again. What explains the Lord of the Flies we commonly see on playgrounds?

The Ghost in the Machine comes from Judeo-Christian philosphy. The soul is this ethereal entity, distinct from our bodies. The soul does not behave according to physical laws (Descartes). Rather, our minds are us, and our bodies might not actually exist. Hobbes tried to convince us that our minds and bodies are mechanical entities, and there is no such thing as free will. We are no different than insects.

Pinker in the argues that genetics drive 50% of our behavior and 50% on the unique environment (as opposed to the shared environment of the home) in our lives. Kids are different, because their genes differ. Identical twins are different, because their peers (and the outside world in general) treat them differently. Parents have little to do with the behavior of their children.

As a parent, the second (home life is irrelevant) and third (peers rule) laws were the hardest to swallow. I see genes at play, but I feel like I'm the cause of my kids bad behavior (and rarely their good behavior, which I attribute to genes). After reading the whole book, I have to say that Pinker makes sense of what I have seen. A trivial but concrete example, my kids talk with a Colorado accent, even though my wife and I are not from here, and we spent most of their "formative" years talking to them as the Good Books say we should. My best friend growing up spoke Spanish with his parents but with a New York accent.

The Blank Slate is an excellent and well-written book. You'll be surprised by the many studies he presents. You might even change your beliefs about parenting and why we act the way we do.

[k608] We realize that no mandarin is wise enough to be entrusted with directing the evolution of the species, and that it is wrong in any case for the government to interfere with such a personal decision as having a child. The very idea that the members of an ethnic group should be persecuted because of their biology fills us with revulsion.

[k614] Most Victorian gentlemen could not have imagined that the coming century would see a nation-state forged by Jewish pioneers and soldiers, a wave of African American public intellectuals, or a software industry in Bangalore. Nor could they have anticipated that women would lead nations in wars, run huge corporations, or win Nobel Prizes in science. We now know that people of both sexes and all races are capable of attaining any station in life.

[k620] The doctrine of the Blank Slate became entrenched in intellectual life in a form that has been called the Standard Social Science Model or social constructionism. The model is now second nature to people and few are aware of the history behind it. Carl Degler,

[k643] John Locke and other Enlightenment thinkers. For Locke the Blank Slate was a weapon against the church and tyrannical monarchs, but these threats had subsided in the English-speaking world by the nineteenth century. Locke's intellectual heir John Stuart Mill (1806--1873) was perhaps the first to apply his blank-slate psychology to political concerns we recognize today. He was an early supporter of women's suffrage, compulsory education, and the improvement of the conditions of the lower classes.

[k667] In behaviorism, an infant's talents and abilities didn't matter because there was no such thing as a talent or an ability.

[k696] Behaviorism not only took over psychology but infiltrated the public consciousness. Watson wrote an influential childrearing manual recommending that parents establish rigid feeding schedules for their children and give them a minimum of attention and love. If you comfort a crying child, he wrote, you will reward him for crying and thereby increase the frequency of crying behavior.

[k701] If we turned society into a big Skinner box and controlled behavior deliberately rather than haphazardly, we could eliminate aggression, overpopulation, crowding, pollution, and inequality, and thereby attain utopia. The noble savage became the noble pigeon.

[k757] But Boas had created a monster. His students came to dominate American social science, and each generation outdid the previous one in its sweeping pronouncements. Boas's students insisted not just that differences among ethnic groups must be explained in terms of culture but that every aspect of human existence must be explained in terms of culture. For example,

I particularly enjoy his references to the tree of followers created by influential thinkers.

[k815] The superorganic or group mind also became an article of faith in social science. Robert Lowie (another Boas student) wrote, "The principles of psychology are as incapable of accounting for the phenomena of culture as is gravitation to account for architectural styles."

[k835] In 1950, for example, he drafted a manifesto for the newly formed UNESCO that declared, "Biological studies lend support to the ethic of universal brotherhood, for man is born with drives toward co-operation, and unless these drives are satisfied, men and nations alike fall ill." With the ashes of thirty-five million victims of World War II still warm or radioactive, a reasonable person might wonder how "biological studies" could show anything of the kind. The draft was rejected,

[k923] The first idea: The mental world can be grounded in the physical world by the concepts of information, computation, and feedback. A great divide between mind and matter has always seemed natural because behavior appears to have a different kind of trigger than other physical events. Ordinary events have causes, it seems, but human behavior has reasons.

[k980] A second idea: The mind cannot be a blank slate, because blank slates don't do anything. As long as people had only the haziest concept of what a mind was or how it might work, the metaphor of a blank slate inscribed by the environment did not seem too outrageous. But as soon as one starts to think seriously about what kind of computation enables a system to see, think, speak, and plan, the problem with blank slates becomes all too obvious: they don't do anything.

[k1024] A third idea: An infinite range of behavior can be generated by finite combinatorial programs in the mind. Cognitive science has undermined the Blank Slate and the Ghost in the Machine in another way. People can be forgiven for scoffing at the suggestion that human behavior is "in the genes" or "a product of evolution" in the senses familiar from the animal world.

[k1047] Once one starts to think about mental software instead of physical behavior, the radical differences among human cultures become far smaller, and that leads to a fourth new idea: Universal mental mechanisms can underlie superficial variation across cultures. Again, we can use language as a paradigm case of the open-endedness of behavior. Humans speak some six thousand mutually unintelligible languages. Nonetheless, the grammatical programs in their minds differ far less than the actual speech coming out of their mouths. We have known for a long time that all human languages can convey the same kinds of ideas.

[k1102] The behaviorists got it backwards: it is the mind, not behavior, that is lawful. A fifth idea: The mind is a complex system composed of many interacting parts. The psychologists who study emotions in different cultures have made another important discovery. Candid facial expressions appear to be the same everywhere, but people in some cultures learn to keep a poker face in polite company.

[k1216] These gross features of the brain are almost certainly not sculpted by information coming in from the senses, which implies that differences in intelligence, scientific genius, sexual orientation, and impulsive violence are not entirely learned. ### The brain could not possibly be wired by the genes down to the last synapse, because there isn't nearly enough information in the genome to do so.

[k1223] Becoming stronger in math or motor coordination or visual discrimination does not bulk up the brain the way becoming stronger at weightlifting bulks up the muscles.

[k1233] Chimpanzees brought up in a human home do not speak, think, or act like people, and that is because of the information in the ten megabytes of DNA that differ between us.

[k1368] Natural selection is the only physical process we know of that can simulate engineering, because it is the only process in which how well something works can play a causal role in how it came to be.

[k1535] THE FIRST STEP in connecting culture to the sciences of human nature is to recognize that culture, for all its importance, is not some miasma that seeps into people through their skin. Culture relies on neural circuitry that accomplishes the feat we call learning. Those circuits do not make us indiscriminate mimics but have to work in surprisingly subtle ways to make the transmission of culture possible.

[k1657] CULTURE, THEN, IS a pool of technological and social innovations that people accumulate to help them live their lives, not a collection of arbitrary roles and symbols that happen to befall them.

[k1885] No one has the slightest idea how many genes it would take to build a system of hard-wired modules, or a general-purpose learning program, or anything in between--to say nothing of original sin or the superiority of the ruling class. In our current state of ignorance of how the genes build a brain, the number of genes in the human genome is just a number.

[k1904] James Watson points out that we should recalibrate our intuitions about what a given number of genes can do: "Imagine watching a play with thirty thousand actors. You'd get pretty confused."

[k2190] Take the development of the body. The genes that build a femur cannot specify the exact shape of the ball on top, because the ball has to articulate with the socket in the pelvis, which is shaped by other genes, nutrition, age, and chance. So the ball and the socket adjust their shapes as they rotate against each other while the baby kicks in the womb. (We know this because experimental animals that are paralyzed while they develop end up with grossly deformed joints.) Similarly, the genes shaping the lens of the growing eye cannot know how far back the retina is going to be or vice versa. So the brain of the baby is equipped with a feedback loop that uses signals about the sharpness of the image on the retina to slow down or speed up the physical growth of the eyeball. These are good examples of "plasticity," but the metaphor of plastic material is misleading. The mechanisms are not designed to allow variable environments to shape variable organs. They do the opposite: they ensure that despite variable environments, a constant organ develops, one that is capable of doing its job.

[k2213] Most evolutionary biologists believe that natural selection can support a genome that is only so big.

[k2227] One of the rules of learning in neural networks, first outlined by the psychologist D. O. Hebb, is that "neurons that fire together wire together; neurons out of synch fail to link." As the waves crisscross the retina for days and weeks, the visual thalamus downstream could organize itself into layers, each from a single eye, with adjacent neurons responding to adjacent parts of the retina. The cortex, in theory,

[k2236] But in the case of Shatz's cats, it works without any environmental input at all. The visual system develops in the pitch-dark womb, before the animal's eyes are open and before its rods and cones are even hooked up and functioning. The retinal waves are generated endogenously by the tissues of the retina during the period in which the visual brain has to wire itself up. In other words, the eye generates a test pattern, and the brain uses it to complete its own assembly. ### the same place in the eye. A rough analogy occurred to me when I watched the cable TV installer figure out which cable in the basement led to a particular room upstairs. He attached a tone generator called a "screamer" to the end in the bedroom and then ran downstairs to listen for the signal on each cable in the bouquet coming out of the wall. Though the cables were designed to carry a television signal upstairs, not a test tone downstairs, they lent themselves to this other use during the installation process because an information conduit is useful for both purposes. The moral is that a discovery that brain development depends on brain activity may say nothing about learning or experience, only that the brain takes advantage of its own information-transmission abilities while wiring itself up.

[k2263] This is simply a corollary of the general point with which I began the chapter: the environment cannot tell the various parts of an organism what their goals are. The doctrine of extreme plasticity has used the plasticity discovered in primary sensory cortex as a metaphor for what happens elsewhere in the brain. The upshot of these two sections is that it is not a very good metaphor. If the plasticity of sensory cortex symbolized the plasticity of mental life as a whole, it should be easy to change what we don't like about ourselves or other people.

[k2274] With a few dubious exceptions (which are probably instances of conscious self-control rather than a change in desire), the sexual orientation of most gay men cannot be reversed by experience. Some parts of the mind just aren't plastic, and no discoveries about how sensory cortex gets wired will change that fact.

[k2280] Neural tissue is not a magical substance that can assume any form demanded of it but a mechanism that obeys the laws of cause and effect. When we take a closer look at the prominent examples of plasticity, we discover that the changes are not miracles after all. In every case, the altered cortex is not doing anything very different from what it ordinarily does.

The word invented struck me oddly when I first read it in this sentence, but it makes sense. When we modify an existing system, we are inventing a new one. We often think of inventions coming out of thin air but they don't. Inventions never occur in a vacuum just like evolution started at the time of the big bang and is going forward incrementally ever since.

[k2360] One team invented a mouse whose synapses were completely shut down, preventing neurons from signaling to one another. Its brain developed fairly normally, complete with layered structures, fiber pathways, and synapses in the right places. (

[k2802] NO ONE SHOULD be surprised that claims about human nature are controversial. Obviously any such claim should be scrutinized and any logical and empirical flaws pointed out, just as with any scientific hypothesis. But the criticism of the new sciences of human nature went well beyond ordinary scholarly debate. It turned into harassment, slurs, misrepresentation, doctored quotations, and, most recently, blood libel.

[k2819] BEHAVIORAL SCIENCE IS not for sissies. Researchers may wake up to discover that they are despised public figures because of some area they have chosen to explore or some datum they have stumbled upon. Findings on certain topics--daycare, sexual behavior, childhood memories, the treatment of substance abuse--may bring on vilification, harassment, intervention by politicians, and physical assault.

Pinker goes to great lengths to discuss the details associated with the anti-behavioral genetics crowd. It does smack of protesting too much. I am convinced already. One refutation or two is enough for me, the layman. No amount of refutations will convince the unconvertable. For them it is about about belief, not science.

[k2881] Lewontin wrote a book whose jacket precis claims that "our genetic endowments confer a plasticity of psychic and physical development, so that in the course of our lives, from conception to death, each of us, irrespective of race, class, or sex, can develop virtually any identity that lies within the human ambit."

[k2904] Twenty years later, Gould wrote that "Homo sapiens is not an evil or destructive species." His new argument comes from what he calls the Great Asymmetry. It is "an essential truth," he writes, that "good and kind people outnumber all others by thousands to one." Moreover, "we perform 10,000 acts of small and unrecorded kindness for each surpassingly rare, but sadly balancing, moment of cruelty." The statistics making up this "essential truth" are pulled out of the air and are certainly wrong: psychopaths, who are definitely not "good and kind people," make up about three or four percent of the male population, not several hundredths of a percent. But even if we accept the figures, the argument assumes that for a species to count as "evil and destructive," it would have to be evil and destructive all the time, like a deranged postal worker on a permanent rampage. It is precisely because one act can balance ten thousand kind ones that we call it "evil." Also,

[k3167] This is exactly the difference between a living animal and a dead one; and I say the same of the moon, of Jupiter, and of all other world globes. ...Those who so greatly exalt incorruptibility, inalterability, et cetera, are reduced to talking this way, I believe, by their great desire to go on living, and by the terror they have of death. They do not reflect that if men were immortal, they themselves would never have come into the world. Such men really deserve to encounter a Medusa's head which would transmute them into statues of jasper or diamond, and thus make them more perfect than they are. Today we see things Galileo's way. It's hard for us to imagine why the three-dimensional arrangement of rock and gas in space should have anything to do with right and wrong or with the meaning and purpose of our lives. The moral sensibilities of Galileo's time eventually adjusted to the astronomical facts, not just because they had to give a nod to reality but because the very idea that morality has something to do with a Great Chain of Being was daffy to begin with.

[k3189] The anxiety about human nature can be boiled down to four fears: If people are innately different, oppression and discrimination would be justified. If people are innately immoral, hopes to improve the human condition would be futile. If people are products of biology, free will would be a myth and we could no longer hold people responsible for their actions. If people are products of biology, life would have no higher meaning and purpose.

[k3195] It's not just that claims about human nature are less dangerous than many people think. It's that the denial of human nature can be more dangerous than people think. This makes it imperative to examine claims about human nature objectively, without putting a moral thumb on either side of the scale, and to figure out how we can live with the claims should they turn out to be true.

One of the more interesting things about science is that it is not fragile. Science simply says that ideas can be tested. Science makes no moral judgments. Morals are difficult if you base them on an externality. Morals are not fragile if you accept you might be wrong about them. You believe them, because they align with your experience. You change them when you learn something new which contradicts your prior experience.

[k3215] The problem is not with the possibility that people might differ from one another, which is a factual question that could turn out one way or the other. The problem is with the line of reasoning that says that if people do turn out to be different, then discrimination, oppression, or genocide would be OK after all. Fundamental values (such as equality and human rights) should not be held hostage to some factual conjecture about blank slates that might be refuted tomorrow. In this chapter we will see how these values might be put on a more secure foundation.

[k3286] SO COULD DISCOVERIES in biology turn out to justify racism and sexism? Absolutely not! The case against bigotry is not a factual claim that humans are biologically indistinguishable. It is a moral stance that condemns judging an individual according to the average traits of certain groups to which the individual belongs. Enlightened societies choose to ignore race, sex, and ethnicity in hiring, promotion, salary, school admissions, and the criminal justice system because the alternative is morally repugnant.

[k3347] The best cure for discrimination, then, is more accurate and more extensive testing of mental abilities, because it would provide so much predictive information about an individual that no one would be tempted to factor in race or gender. (This, however, is an idea with no political future.)

[k3359] Denying driving and voting rights to young teenagers is a form of age discrimination that is unfair to responsible teens. But we are not willing to pay either the financial costs of developing a test for psychological maturity or the moral costs of classification errors, such as teens wrapping their cars around trees. Almost everyone is appalled by racial profiling--pulling over motorists for "driving while black." But after the 2001 terrorist attacks on the World Trade Center and the Pentagon, about half of Americans polled said they were not opposed to ethnic profiling--scrutinizing passengers for "flying while Arab." People who distinguish the two must reason that the benefits of catching a marijuana dealer do not outweigh the harm done to innocent black drivers, but the benefits of stopping a suicide hijacker do outweigh the harm done to innocent Arab passengers. Cost-benefit analyses are also sometimes used to justify racial preferences: the benefits of racially diverse workplaces and campuses are thought to outweigh the costs of discriminating against whites.

[k3464] Moreover, a given gene can lead to different behavior in different environments. When the biochemist (and radical scientist) George Wald was solicited for a semen sample by William Shockley's sperm bank for Nobel Prize--winning scientists, he replied, "If you want sperm that produces Nobel Prize winners you should be contacting people like my father, a poor immigrant tailor. What have my sperm given the world? Two guitarists!"

[k3479] The history of eugenics is one of many cases in which the moral problems posed by human nature cannot be folded into familiar left-right debates but have to be analyzed afresh in terms of the conflicting values at stake.

[k3556] Nazism and Marxism shared a desire to reshape humanity. "The alteration of men on a mass scale is necessary," wrote Marx; "the will to create mankind anew" is the core of National Socialism, wrote Hitler. They also shared a revolutionary idealism and a tyrannical certainty in pursuit of this dream, with no patience for incremental reform or adjustments guided by the human consequences of their policies. This alone was a recipe for disaster.

[k3702] As soon as we recognize that there is nothing morally commendable about the products of evolution, we can describe human psychology honestly, without the fear that identifying a "natural" trait is the same as condoning it.

[k3760] If, however, the mind is a system with many parts, then an innate desire is just one component among others. Some faculties may endow us with greed or lust or malice, but others may endow us with sympathy, foresight, self-respect, a desire for respect from others, and an ability to learn from our own experiences and those of our neighbors.

Our choices are affected by anxiety which in turn affects our choices. Like any system you can choose to use this feedback negatively or positively, but you cannot simply pretend it is not part of the system.

[k3925] One fear of determinism is a gaping existential anxiety: that deep down we are not in control of our own choices. All our brooding and agonizing over the right thing to do is pointless, it would seem, because everything has already been preordained by the state of our brains. If you suffer from this anxiety, I suggest the following experiment. For the next few days, don't bother deliberating over your actions. It's a waste of time, after all; they have already been determined. Shoot from the hip, live for the moment, and if it feels good do it. No, I am not seriously suggesting that you try this! But a moment's reflection on what would happen if you did try to give up making decisions should serve as a Valium for the existential anxiety. The experience of choosing is not a fiction, regardless of how the brain works. It is a real neural process, with the obvious function of selecting behavior according to its foreseeable consequences. It responds to information from the senses, including the exhortations of other people. You cannot step outside it or let it go on without you because it is you. If the most ironclad form of determinism is real, you could not do anything about it anyway, because your anxiety about determinism, and how you would deal with it, would also be determined. It is the existential fear of determinism that is the real waste of time.

Choice requires change, that is, to acknowledge the universe is in flux and we must react at a conscious level to its whims. John Conway has a mathematical proof of the existence of Free Will by starting with the non-determinism inherent in quantum theory. At the end of the proof he says that some people would call this Free Whim, and I agree with that. It is impossible to define Free Will any other way. To do so would be to eliminate some freedom in it by constraining it. It is a bit like the Heisenberg Principle.

[k3938] But when we attribute an action to a person's brain, genes, or evolutionary history, it seems that we no longer hold the individual accountable. Biology becomes the perfect alibi, the get-out-of-jail-free card, the ultimate doctor's excuse note. As we have seen, this accusation has been made by the religious and cultural right, who want to preserve the soul, and the academic left, who want to preserve a "we" who can construct our own futures though in circumstances not of our own choosing.

[k3975] Morality and law would be pointless. We could punish a wrongdoer, but it would be sheer spite, because it could have no predictable effect on the future behavior of the wrongdoer or of other people aware of the punishment. On the other hand, if the soul is predictably affected by the prospect of esteem and shame or reward and punishment, it is no longer truly free, because it is compelled (at least probabilistically) to respect those contingencies. What-ever converts standards of responsibility into changes in the likelihood of behavior--such as the rule "If the community would think you're a boorish cad for doing X, don't do X"--can be programmed into an algorithm and implemented in neural hardware. The soul is superfluous.

[k3991] Perhaps the brain amplifies random events at the molecular or quantum level. Perhaps brains are nonlinear dynamical systems subject to unpredictable chaos. Or perhaps the intertwined influences of genes and environment are so complicated that no mortal will ever trace them out with enough precision to predict behavior exactly.

[k4210] 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.

[k4225] 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 interests 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).

[k4485] Yes, every snowflake is unique, and no category will do complete justice to every one of its members. But intelligence depends on lumping together things that share properties, so that we are not flabbergasted by every new thing we encounter.

[k4827] But we can best protect ourselves against such manipulation by pinpointing the vulnerabilities of our faculties of categorization, language, and imagery, not by denying their complexity. The view that humans are passive receptacles of stereotypes, words, and images is condescending to ordinary people and gives unearned importance to the pretensions of cultural and academic elites. And exotic pronouncements about the limitations of our faculties, such as that there is nothing outside the text or that we inhabit a world of images rather than a real world, make it impossible even to identify lies and misrepresentations, let alone to understand how they are promulgated.

[k4895] Traditional education is based in large part on the Blank Slate: children come to school empty and have knowledge deposited in them, to be reproduced later on tests. (Critics of traditional education call this the "savings and loan" model.)

[k4899] Progressive educational practice, for its part, is based on the Noble Savage. As A. S. Neill wrote in his influential book Summerhill, "A child is innately wise and realistic. If left to himself without adult suggestion of any kind, he will develop as far as he is capable of developing." Neill and other progressive theorists of the 1960s and 1970s argued that schools should do away with examinations, grades, curricula, and even books. Though few schools went that far,

[k4906] Both methods fare badly when students' learning is assessed objectively, but advocates of the methods tend to disdain standardized testing. An understanding of the mind as a complex system shaped by evolution runs against these philosophies.

[k4910] Rather, education is a technology that tries to make up for what the human mind is innately bad at. Children don'

[k4913] Far from being empty receptacles or universal learners, then, children are equipped with a toolbox of implements for reasoning and learning in particular ways, and those implements must be cleverly recruited to master problems for which they were not designed. That requires not just inserting new facts and skills in children's minds but debugging and disabling old ones. Students ### cannot learn Newtonian physics until they unlearn their intuitive impetus-based physics. They cannot learn modern biology until they unlearn their intuitive biology, which thinks in terms of vital essences. And they cannot learn evolution until they unlearn their intuitive engineering, which attributes design to the intentions of a designer.

[k4928] Geary points out a final implication. Because much of the content of education is not cognitively natural, the process of mastering it may not always be easy and pleasant, notwithstanding the mantra that learning is fun. Children may be innately motivated to make friends, acquire status, hone motor skills, and explore the physical world, but they are not necessarily motivated to adapt their cognitive faculties to unnatural tasks like formal mathematics. A family, peer group,

[k4954] In the face of these difficult choices it is tempting to look to biology to find or ratify boundaries such as "when life begins." But that only highlights the clash between two incommensurable ways of conceiving life and mind. The intuitive and morally useful concept of an immaterial spirit simply cannot be reconciled with the scientific concept of brain activity emerging gradually in ontogeny and phylogeny. No matter where we try to draw the line between life and nonlife, or between mind and nonmind, ambiguous cases pop up to challenge our moral intuitions.

[k4960] The Catholic Church and certain other Christian denominations designate conception as the moment of ensoulment and the beginning of life (which, of course, makes abortion a form of murder). But just as a microscope reveals that a ### conception" is not a moment at all. Sometimes several sperm penetrate the outer membrane of the egg, and it takes time for the egg to eject the extra chromosomes. What and where is the soul during this interval?

[k4964] So the "moment" of conception is in fact a span of twenty-four to forty-eight hours.

[k4968] The soul, by this reasoning, may be identified with the genome. But during the next few days, as the embryo's cells begin to divide, they can split into several embryos, which develop into identical twins, triplets, and so on. ### Do identical twins share a soul? Did the Dionne quintuplets make do with one-fifth of a soul each? If not, where did the four extra souls come from? Indeed, every cell in the growing embryo is capable, with the right manipulations, of becoming a new embryo that can grow into a child. Does a multicell embryo consist of one soul per cell, and if so, where do the other souls go when the cells lose that ability? And not only can one embryo become two people, but two embryos can become one person. Occasionally two fertilized eggs, which ordinarily would go on to become fraternal twins, merge into a single embryo that develops into a person who is a genetic chimera: some of her cells have one genome, others have another genome.

[k4975] For that matter, if human cloning ever became possible (and there appears to be no technical obstacle), every cell in a person's body would have the special ability that is supposedly unique to a conceptus, namely developing into a human being. True, the genes in a cheek cell can become a person only with unnatural intervention, but that is just as true for an egg that is fertilized in vitro. Yet no one would deny that children conceived by IVF have souls. The idea that ensoulment takes place at conception is not only hard to reconcile with biology but does not have the moral superiority credited to it.

[k4991] The belief that bodies are invested with souls is not just a product of religious doctrine but embedded in people's psychology and likely to emerge whenever they have not digested the findings of biology.

[k4998] Clones, in fact, are just identical twins born at different times. If Einstein had a twin, he would not have been a zombie, would not have continued Einstein's stream of consciousness if Einstein had predeceased him, would not have given up his vital organs without a struggle, and probably would have been no Einstein (since intelligence is only partly heritable).

[k5007] The discovery that what we call "the person" emerges piecemeal from a gradually developing brain forces us to reframe problems in bioethics.

[k5034] There is no solution to these dilemmas, because they arise out of a fundamental incommensurability: between our intuitive psychology, with its all-or-none concept of a person or soul, and the brute facts of biology, which tell us that the human brain evolved gradually, develops gradually, and can die gradually. And that means that moral conundrums such as abortion, euthanasia, and animal rights will never be resolved in a decisive and intuitively satisfying way. This does not mean that no policy ### dogma. As the bioethicist Ronald Green has pointed out, it just means we have to reconceptualize the problem: from finding a boundary in nature to choosing a boundary that best trades off the conflicting goods and evils for each policy dilemma.

[k5054] WHEN A 1999 CYCLONE in India left millions of people in danger of starvation, some activists denounced relief societies for distributing a nutritious grain meal because it contained genetically modified varieties of corn and soybeans (varieties that had been eaten without apparent harm in the United States).

[k5061] A 2001 report by the European Union reviewed eighty-one research projects conducted over fifteen years and failed to find any new risks to human health or to the environment posed by genetically modified crops. This is no surprise to a biologist. Genetically modified foods are no more dangerous than "natural" foods because they are not fundamentally different from natural foods. Virtually every animal and vegetable sold in a health-food store has been "genetically modified" for millennia by selective breeding and hybridization.

[k5068] So there is nothing especially safe about natural foods. The "natural" method of selective breeding for pest resistance simply increases the concentration of the plant's own poisons; one variety of natural potato had to be withdrawn from the market because it proved to be toxic to people. Similarly,

[k5105] They clamor for expensive measures to get chloroform and trichloroethylene out of drinking water, though they are hundreds of times more likely to get cancer from a daily peanut butter sandwich (since peanuts can carry a highly carcinogenic mold).

[k5143] Nonetheless, understanding the difference between our best science and our ancient ways of thinking can only make our individual and collective decisions better informed.

[k5176] Economists refer to "the physical fallacy": the belief that an object has a true and constant value, as opposed to being worth only what someone is willing to pay for it at a given place and time. This is simply the difference between the Equality Matching and Market Pricing mentalities.

[k5204] The perilous fallacies we have seen in this chapter, for example, would give high priority to economics, evolutionary biology, and probability and statistics in any high school or college curriculum. Unfortunately, most curricula have barely changed since medieval times, and are barely changeable, because no one wants to be the philistine who seems to be saying that it is unimportant to learn a foreign language, or English literature, or trigonometry, or the classics.

[k5240] The immediate problem with Malthusian prophecies is that they underestimate the effects of technological change in increasing the resources that support a comfortable life.

[k5248] But recently the economist Paul Romer has invoked the combinatorial nature of cognitive information processing to show how the circle might be squared after all. He begins by pointing out that human material existence is limited by ideas, not by stuff. People don'

[k5253] For example, petroleum used to be just a contaminant of water wells; then it became a source of fuel, replacing the declining supply of whale oil. Sand was once used to make glass; now it is used to make microchips and optical fiber. Romer's second point is that ideas are what economists call "nonrival goods." Rival goods, such as food, fuel, and tools, are made of matter and energy. If one person uses them, others cannot, as we recognize in the saying "You can't eat your cake and have it." But ideas are made of information, which can be duplicated at negligible cost. A recipe for bread, a blueprint for a building, ### from the giver. The seemingly magical proliferation of nonrival goods has recently confronted us with new problems concerning intellectual property, as we try to adapt a legal system that was based on owning stuff to the problem of owning information--such as musical recordings--that can easily be shared over the Internet.

[k5264] Human practical intelligence may have co-evolved with language (which allows know-how to be shared at low cost) and with social cognition (which allows people to cooperate without being cheated), yielding a species that literally lives by the power of ideas.

[k5317] or "elegant." Trivers derived the first theory in social psychology that deserves to be called elegant. He showed that a deceptively simple principle--follow the genes--can explain the logic of each of the major kinds of human relationships: how we feel toward our parents, our children, our siblings, our lovers, our friends, and ourselves. But Trivers knew that the theory did something else as well. It offered a scientific explanation for the tragedy of the human condition.

[k5329] It's no mystery why organisms sometimes harm one another. Evolution has no conscience, and if one creature hurts another to benefit itself, such as by eating, parasitizing, intimidating, or cuckolding it, its descendants will come to predominate, complete with those nasty habits. All this is familiar from the vernacular sense of "Darwinian" as a synonym for "ruthless" and from Tennyson's depiction of nature as red in tooth and claw. If that were all there was to the evolution of the human condition, we would have to agree with the rock song: Life sucks, then you die.

[k5370] Nothing prevents the amoral process of natural selection from evolving a brain with genuine big-hearted emotions. It is said that those who appreciate legislation and sausages should not see them being made. The same is true for human emotions.

[k5375] Thus every human relationship, even the most devoted and intimate, carries the seeds of conflict. In the movie AntZ,

[k5404] Moral philosophers play with a hypothetical dilemma in which people can run through the left door of a burning building to save some number of children or through the right door to save their own child. If you are a parent, ponder this question: Is there any number of children that would lead you to pick the left door? Indeed, all of us reveal our preference with our pocketbooks when we spend money on trifles for our own children (a bicycle, orthodontics, an education at a private school or university) instead of saving the lives of unrelated children in the developing world by donating the money to charity.

[k5814] In a pithy and now-famous passage, Trivers wrote: If...deceit is fundamental to animal communication, then there must be strong selection to spot deception and this ought, in turn, to select for a degree of self-deception, rendering some facts and motives unconscious so as not to betray--by the subtle signs of self-knowledge--the deception being practiced. Thus, the conventional view that natural selection favors nervous systems which produce ever more accurate images of the world must be a very naive view of mental evolution.

[k5828] The theory of self-deception was foreshadowed by the sociologist Erving Goffman in his 1959 book The Presentation of Self in Everyday Life, which disputed the romantic notion that behind the masks we show other people is the one true self. No, said Goffman; it's masks all the way down. Many discoveries in the ensuing decades have borne him out. Though modern psychologists and psychiatrists tend to reject orthodox Freudian theory, many acknowledge that Freud was right about the defense mechanisms of the ego. Any therapist will tell you that people protest too much, deny or repress unpleasant facts, project their flaws onto others, turn their discomfort into abstract intellectual problems, distract themselves with time-consuming activities, and rationalize away their motives.

[k5853] Self-deception is among the deepest roots of human strife and folly. It implies that the faculties that ought to allow us to settle our differences--seeking the truth and discussing it rationally--are miscalibrated so that all parties assess themselves to be wiser, abler, and nobler than they really are. Each party to a dispute can sincerely believe that the logic and evidence are on his side and that his opponent is deluded or dishonest or both. Self-deception is one of the reasons that the moral sense can, paradoxically, often do more harm than good, a human misfortune we will explore in the next chapter.

[k5941] Consider this story: Julie and Mark are brother and sister. They are traveling together in France on summer vacation from college. One night they are staying alone in a cabin near the beach. They decide that it would be interesting and fun if they tried making love. At the very least it would be a new experience for each of them. Julie was already taking birth control pills, but Mark uses a condom too, just to be safe. They both enjoy making love, but they decide not to do it again. They keep the night as a special secret, which makes them feel even closer to each other. What do you think about that; was it OK for them to make love? The psychologist Jonathan Haidt and his colleagues have presented the story to many people. Most immediately declare that what Julie and Mark did was wrong, and then they grope for reasons why it was wrong. They mention the dangers of inbreeding, but they are reminded that the siblings used two forms of contraception. They suggest that Julie and Mark will be emotionally hurt, but the story makes it clear that they were not. They venture that the act would offend the community, but then they recall that it was kept secret. They submit that it might interfere with future ### relationships, but they acknowledge that Julie and Mark agreed never to do it again. Eventually many of the respondents admit, "I don't know, I can't explain it, I just know it's wrong." Haidt calls this "moral dumbfounding" and has evoked it by other disagreeable but victimless scenarios:

[k6035] The difference between a defensible moral position and an atavistic gut feeling is that with the former we can give reasons why our conviction is valid. We can explain why torture and murder and rape are wrong, or why we should oppose discrimination and injustice. On the other hand, no good reasons can be produced to show why homosexuality should be suppressed or why the races should be segregated. And the good reasons for a moral position are not pulled out of thin air: they always have to do with what makes people better off or worse off, and are grounded in the logic that we have to treat other people in the way that we demand they treat us.

The are two kinds of people... I am an environmental vegetarian. I do not eat meat unless it is going to be thrown away and I am hungry.

[k6044] There are two kinds of vegetarians: those who avoid meat for health reasons, namely reducing dietary fat and toxins, and those who avoid meat for moral reasons, namely respecting the rights of animals.

[k6127] Americans' health was debatable. After the Exxon Valdez oil spill, four-fifths of the respondents in one poll said that the country should pursue greater environmental protection "regardless of cost." Taken literally, that meant they were prepared to shut down all schools, hospitals, and police and fire stations, stop funding social programs, medical research, foreign aid, and national defense, or raise the income tax rate to 99 percent, if that is what it would have cost to protect the environment.

[k6237] With a slightly different ecosystem and evolutionary history, we could have ended up like our cousins the orangutans, who are almost entirely solitary. And according to evolutionary biology, all societies--animal and human--seethe with conflicts of interest and are held together by shifting mixtures of dominance and cooperation.

[k6306] In the Tragic Vision, moreover, human nature has not changed. Traditions such as religion,

[k6310] We are fortunate enough to live in a society that more or less works, and our first priority should be not to screw it up, because human nature always leaves us teetering on the brink of barbarism. And since no one is smart enough to predict the behavior of a single human being, let alone millions of them interacting in a society, we should distrust any formula for changing society from the top down, because it is likely to have unintended consequences that are worse than the problems it was designed to fix. The best we can hope for are incremental changes that are continuously adjusted according to feedback about the sum of their good and bad consequences.

[k6321] In the Utopian Vision, human nature changes with social circumstances, so traditional institutions have no inherent value.

[k6327] Moreover, the existence of suffering and injustice presents us with an undeniable moral imperative. We don't know what we can achieve until we try, and the alternative, resigning ourselves to these evils as the way of the world, is unconscionable.

[k6501] How to anticipate and limit that corruption became an obsession of the framers. John Adams wrote, "The desire for the esteem of others is as real a want of nature as hunger. It is the principal end of government to regulate this passion." Alexander Hamilton wrote, "The love of fame [is] the ruling passion of the noblest minds." James Madison wrote, "If men were angels, no government would be necessary. If angels were to govern men, neither external nor internal controls on government would be necessary."

[k6543] For all its selfishness, the human mind is equipped with a moral sense, whose circle of application has expanded steadily and might continue to expand as more of the world becomes interdependent. And for all its limitations, human cognition is an open-ended combinatorial system, which in principle can increase its mastery over human affairs, just as it has increased its mastery of the physical and living worlds.

Pinker is all over the space of philosophical thought. I think he does a good job but it is hard to follow unless you are used to associative thinking in the extreme.

[k6584] Chomsky's political beliefs, then, resonate with his scientific belief that humans are innately endowed with a desire for community and a drive for creative free expression, language being the paradigm example. That holds out the hope for a society organized by cooperation and natural productivity rather than by hierarchical control and the profit motive. Chomsky's theory of human nature, though strongly innatist, is innocent of modern evolutionary biology, with its demonstration of ubiquitous conflicts of genetic interest. These conflicts lead to a darker view of human nature, one that has always been a headache for those with anarchist dreams. But the thinker who first elucidated these conflicts, Robert Trivers, was a left-wing radical as well, and one of the rare white Black Panthers. As we saw in Chapter 6, Trivers viewed sociobiology as a subversive discipline.

[k6614] An important challenge to conservative political theory has come from behavioral economists such as Richard Thaler and George Akerlof, who were influenced by the evolutionary cognitive psychology of Herbert Simon, Amos Tversky, Daniel Kahneman, Gerd Gigerenzer, and Paul Slovic. These psychologists have argued that human thinking and decision making are biological adaptations rather than engines of pure rationality. These mental systems work with limited amounts of information, have to reach decisions in a finite amount of time, and ultimately serve evolutionary goals such as status and security.

[k6635] The rub, Frank points out, is that people are endowed with a craving for status. Their first impulse is to spend money in ways that put themselves ahead of the Joneses (houses, cars, clothing, prestigious educations), rather than in ways that only they know about (health care, job safety, retirement savings). Unfortunately, status is a zero-sum game, so when everyone has more money to spend on cars and houses, the houses and cars get bigger but people are no happier than they were before. Like hockey players who agree to wear helmets only if a rule forces their opponents to wear them too, people might agree to regulations that force everyone to pay for hidden benefits like health care that make them happier in the long run, even if the regulations come at the expense of disposable income. For the same reason, Frank argues, we would be better off if we implemented a steeply graduated tax on consumption, replacing the current graduated tax on income. A consumption tax would damp down the futile arms race for ever more lavish cars, houses, and watches and compensate people with resources that provably increase happiness, such as leisure time, safer streets, and more pleasant commuting and working conditions.

[k6661] But if people's sense of well-being comes from an assessment of their social status, and social status is relative, then extreme inequality can make people on the lower rungs feel defeated even if they are better off than most of humanity. It is not just a matter of hurt feelings: people with lower status are less healthy and die younger, and communities with greater inequality have poorer health and shorter life expectancies. The medical researcher Richard Wilkinson, who documented these patterns, argues that low status triggers an ancient stress reaction that sacrifices tissue repair and immune function for an immediate fight-or-flight response. Wilkinson,

[k6668] Wilkinson argues that reducing economic inequality would make millions of lives happier, safer, and longer. This well-populated gallery of left-wing innatists should not come as a surprise, even after centuries in which human nature was a preserve of the right. Mindful both of science and of history, the Darwinian left has abandoned the Utopian Vision that brought so many unintended disasters. Whether this non-Utopian left is really all that different from the contemporary secular right, and whether its particular policies are worth their costs, is not for me to argue here. The point is that traditional political alignments ought to change as we learn more about human beings. The ideologies of the left and the right took shape before Darwin, before Mendel, before anyone knew what a gene or a neuron or a hormone was. Every student of political science is taught that political ideologies are based on theories of human nature. Why must they be based on theories that are three hundred years out of date?

[k6745] When culture is seen as an entity with beliefs and desires, the beliefs and desires of actual people are unimportant. After Timothy McVeigh blew up a federal office building in Oklahoma City in 1995, killing 168 people, the journalist Alfie Kohn ridiculed Americans who "yammer about individual responsibility" and attributed the bombing to American individualism: "We have a cultural addiction to competition in this country. We're taught in classrooms and playing fields that other people are obstacles to our own success."

[k6835] Crime in America. In arguing that the criminal justice system should replace punishment with rehabilitation, Clark explained: The theory of rehabilitation is based on the belief that healthy, rational people will not injure others, that they will understand that the individual and his society are best served by conduct that does not inflict injury, and that a just society has the ability to provide health and purpose and opportunity for all its citizens. Rehabilitated, an individual will not have the capacity--cannot bring himself--to injure another or take or destroy property. Would that it were so! This theory is a fine example of the moralistic fallacy: it would be so nice if the idea were true that we should all believe that it is true. The problem is that it is not true. History has shown that plenty of healthy, rational people can bring themselves to injure others and destroy property because, tragically, an individual's interests sometimes are served by hurting others (especially if criminal penalties for hurting others are eliminated, an irony that Clark seems to have missed).

[k6853] The Blank Slate and the Noble Savage owe their support not just to their moral appeal but to enforcement by ideology police. The blood libel against Napoleon Chagnon for documenting warfare among the Yanomamo is the most lurid example of the punishment of heretics, but it is not the only one. In 1992 a Violence Initiative in the Alcohol, Drug Abuse, and Mental Health Administration was canceled because of false accusations that the research aimed to sedate inner-city youth and to stigmatize them as genetically prone to violence. (In fact, it advocated the public health approach.) A conference and book on the legal and moral issues surrounding the biology of violence, which was to include advocates of all viewpoints, was canceled by Bernadine Healey, director of the National Institutes of Health, who overruled a unanimous peer-review decision because of concerns "associated with the sensitivity and validity of the proposed conference." The university sponsoring the conference appealed and won, but when the conference was held three years later, protesters invaded the hall and, as if to provide material for comedians, began a shoving match with the participants.

[k6874] There can be little doubt that some individuals are constitutionally more prone to violence than others. Take men, for starters: across cultures, men kill men twenty to forty times more often than women kill women. And the lion's share of the killers are young men, between the ages of fifteen and thirty. Some young men, moreover, are more violent than others. According to one estimate, 7 percent of young men commit 79 percent of repeated violent offenses. Psychologists find that individuals prone to violence have a distinctive personality profile. They tend to be impulsive, low in intelligence, hyperactive, and attention-deficient. They are described as having an "oppositional temperament": they are vindictive, easily angered, resistant to control, deliberately annoying, and likely to blame everything on other people. The most callous among them are psychopaths, people who lack a conscience, and they make up a substantial percentage of murderers. These traits emerge in early childhood, persist through the lifespan, and are largely heritable, though nowhere near completely so.

[k7064] Our species' vaunted ability to make tools is one of the reasons we are so good at killing one another.

[k7095] A READINESS TO inflict a preemptive strike is a double-edged sword, because it makes one an inviting target for a preemptive strike.

[k7138] Because of the logic of deterrence, fights over personal or national honor are not as idiotic as they seem. In a hostile milieu, people and countries must advertise their willingness to retaliate against anyone who would profit at their expense, and that means maintaining a reputation for avenging any slight or trespass, no matter how small. They must make it known that,

[k7353] But denying the logic of violence makes it easy to forget how readily violence can flare up, and ignoring the parts of the mind that ignite violence makes it easy to overlook the parts that can extinguish it. With violence, as with so many other concerns, human nature is the problem, but human nature is also the solution.

[k7688] But there is something odd in these stories about negative messages, hidden barriers, and gender prejudices. The way of science is to lay out every hypothesis that could account for a phenomenon and to eliminate all but the correct one. Scientists prize the ability to think up alternative explanations, and proponents of a hypothesis are expected to refute even the unlikely ones. Nonetheless, discussions of the leaky pipeline in science rarely even mention an alternative to the theory of barriers and bias.

[k7708] That the presidents of the nation's elite universities are happy to accuse their colleagues of shameful prejudice without even considering alternative explanations (whether or not they would end up accepting them) shows how deeply rooted the taboo is. The problem with this analysis is that inequality of outcome cannot be used as proof of inequality of opportunity unless the groups being compared are identical in all of their psychological traits, which is likely to be true only if we are blank slates. But the suggestion that the gender gap may arise, even in part, from differences between the sexes can be fightin' words. Anyone bringing it up is certain to be accused of "wanting to keep women in their place" or "justifying the status quo." This makes about as much sense as saying that a scientist who studies why women live longer than men "wants old men to die."

[k7839] And it is grotesque to demand (as advocates of gender parity did in the pages of Science) that more young women "be conditioned to choose engineering," as if they were rats in a Skinner box.

[k7952] Scientific research on rape and its connections to human nature was thrown into the spotlight in 2000 with the publication of A Natural History of Rape. Thornhill and Palmer began with a basic observation: a rape can result in a conception, which could propagate the genes of the rapist, including any genes that had made him likely to rape. Therefore, a male psychology that included a capacity to rape would not have been selected against, and could have been selected for. Thornhill and Palmer argued that rape is unlikely to be a typical mating strategy because of the risk of injury at the hands of the victim and her relatives and the risk of ostracism from the community. But it could be an opportunistic tactic, becoming more likely when the man is unable to win the consent of women, alienated from a community (and thus undeterred by ostracism), and safe from detection and punishment (such as in wartime or pogroms). Thornhill and Palmer then outlined two theories. Opportunistic rape could be a Darwinian adaptation that was specifically selected for, as in certain insects that have an appendage with no function other than restraining a female during forced copulation. Or rape could be a by-product of two other features of the male mind: a desire for sex and a capacity to engage in opportunistic violence in pursuit of a goal. The two authors disagreed on which hypothesis was better supported by the data, and they left that issue unresolved.

[k7968] Palmer's hypothesis that rape is on a continuum with the rest of male sexuality makes them strange allies with the most radical gender feminists, such as Catharine MacKinnon and Andrea Dworkin, who said that "seduction is often difficult to distinguish from rape. In seduction, the rapist often bothers to buy a bottle of wine."

[k8118] "The nature-nurture debate is over." So begins a recent article [by Eric Turkheimer] -- "The Three Laws of Behavior Genetics and What They Mean" -- as audacious as its opening sentence.

[k8125] [Turkheimer] was summarizing a body of empirical results that are unusually robust by the standards of psychology.

[k8129] The three laws of behavior genetics may be the most important discoveries in the history of psychology. Yet most psychologists not come to grips with them, and most intellectuals do not understand them, even when they have been explained in the cover stories of newsmagazines. It is not because the laws are abstruse: each can be stated in a sentence, without mathematical paraphernalia. Rather, it is because the laws run roughshod over the Blank Slate, and the Blank Slate is so entrenched that many intellectuals cannot comprehend an alternative to it, let alone argue about whether it is right or wrong.

[k8144] THE FIRST LAW: All human behavioral traits are heritable. Let's begin at the beginning.

[k8199] The First Law implies that any study that measures something in parents and something in their biological children and then draws conclusions about the effects of parenting is worthless, because the correlations may simply reflect their shared genes (aggressive parents may breed aggressive children, talkative parents talkative children). But these expensive studies continue to be done and continue to be translated into parenting advice as if the heritability of all traits were zero.

[k8260] "Genetic determinism!" I have already commented on this odd reflex in modern intellectual life: when it comes to genes, people suddenly lose their ability to distinguish 50 percent from 100 percent, "some" from "all," "affects" from "determines." The diagnosis for this intellectual crippling is clear: if the effects of the genes must, on theological grounds, be zero, then all nonzero values are equivalently heretical.

[k8265] THE SECOND LAW: The effect of being raised in the same family is smaller than the effect of the genes.

[k8285] So what do we find? The effects of shared environment are small (less than 10 percent of the variance), often not statistically significant, often not replicated in other studies, and often a big fat zero. Turkheimer was cautious in saying that the effects are smaller than those of the genes. Many behavioral geneticists go farther and say that they are negligible, particularly in adulthood. (IQ is affected by the shared environment in childhood, but over the years the effect peters out to nothing.)

[k8308] THE THIRD LAW: A substantial portion of the variation in complex human behavioral traits is not accounted for by the effects of genes or families. This follows directly from the First Law, assuming that heritabilities are less than one, and the Second Law. If we carve up the variation among people into the effects of the genes, the shared environment, and the unique environment, and if the effects of the genes are greater than zero and less than one, and if the effects of the shared environment hover around zero, then the effects of the unique environment must be greater than zero. In fact, they are around 50 percent,

[k8317] A handy summary of the three laws is this: Genes 50 percent, Shared Environment 0 percent, Unique Environment 50 percent (or if you want to be charitable, Genes 40--50 percent, Shared Environment 0--10 percent, Unique Environment 50 percent).

[k8332] It was Rousseau who made parents and children the main actors in the human drama. Children are noble savages, and their upbringing and education can either allow their essential nature to blossom or can saddle them with the corrupt baggage of civilization. Twentieth-century versions of the Noble Savage and the Blank Slate kept parents and children at center stage. The behaviorists claimed that children are shaped by contingencies of reinforcement, and advised parents not to respond to their children's distress because it would only reward them for crying and increase the frequency of crying behavior. Freudians theorized that we are shaped by our degree of success in weaning, toilet training, and identification with the parent of the same sex, and advised parents not to bring infants into their beds because it would arouse damaging sexual desires. Everyone theorized that psychological disorders could be blamed on mothers: autism on their coldness, schizophrenia on their "double binds," anorexia on their pressure on girls to be perfect. Low self-esteem was attributed to "toxic parents" and every other problem to "dysfunctional families." Patients in many forms of psychotherapy while away their fifty minutes reliving childhood conflicts, and most biographies scavenge through the subject's childhood for the roots of the grownup's tragedies and triumphs. By now most well-educated parents believe that their children's fates are in their hands. They want their children to be popular and self-confident, to get good grades and stay in school, to avoid drugs, alcohol, and cigarettes, to avoid getting pregnant or fathering a child while a teenager, to stay on the right side of the law, and to become happily married and professionally successful. A parade of parenting experts has furnished them with advice, ever changing in content, never changing in certitude, on how to attain that outcome.

[k8398] But surely the advice is grounded in research on children's development? Yes, from the many useless studies that show a correlation between the behavior of parents and the behavior of their biological children and conclude that the parenting shaped the child, as if there were no such thing as heredity. And in fact the studies are even worse than that. Even if there were no such thing as heredity, a correlation between parents and children would not imply that parenting practices shape children. It could imply that children shape parenting practices. As any parent of more than one child knows, children are not indistinguishable lumps of raw material waiting to be shaped. They are little people, born with personalities. And people react to the personalities of other people, even if one is a parent and the other a child. The parents of an affectionate child may return that affection and thereby act differently from the parents of a child who squirms and wipes off his parents' kisses. The parents of a quiet, spacey child might feel they are talking to a wall and jabber at him less. The parents of a docile child can get away with setting firm but reasonable limits; the parents of a hellion might find themselves at their wits' end and either lay down the law or give up.

[k8421] ...Perhaps what misled those eighteen federal agencies into thinking they were getting their 25 million dollars worth was the positive way the researchers phrased their findings: good relationships with parents exert a protective effect. Expressed in a different (but equally accurate) way, the results sound less interesting: adolescents who don't get along well with their parents are more likely to use drugs or engage in risky sex. The results sound still less interesting expressed this way: adolescents who use drugs or engage in risky sex don't get along well with their parents.

[k8456] In his book The Myth of the First Three Years, the cognitive neuroscience expert Jon Bruer showed that there was no science behind these astonishing claims. No psychologist has ever documented a critical period for cognitive or language development that ends at three. And though depriving an animal of stimulation (by sewing an eye shut or keeping it in a barren cage) may hurt its brain growth, there is no evidence that providing extra stimulation (beyond what the organism would encounter in its normal habitat) enhances its brain growth.

[k8653] SO HAS HARRIS solved the mystery of the Third Law, the unique environment that comes neither from the genes nor from the family? Not exactly. I am convinced that children are socialized--that they acquire the values and skills of the culture--in their peer groups, not their families. But I am not convinced, at least not yet, that peer groups explain how children develop their personalities: why they turn out shy or bold, anxious or confident, open-minded or old-school. Socialization and the development of personality are not the same thing, and peers may explain the first without necessarily explaining the second.

[k8665] Let's return to our touchstone: identical twins growing up together. They share their genes, they share their family environments, and they share their peer groups, at least on average. But the correlations between them are only around 50 percent. Ergo, neither genes nor families nor peer groups can explain what makes them different.

[k8717] People are appalled by human cloning and its dubious promise that parents can design their children by genetic engineering. But how different is that from the fantasy that parents can design their children by how they bring them up? Realistic parents would be less anxious parents. They could enjoy their time with their children rather than constantly trying to stimulate them, socialize them, and improve their characters. They could read stories to their children for the pleasure of it, not because it's good for their neurons. Many critics accuse Harris of trying to absolve parents of responsibility for their children's lives: if the kids turn out badly, parents can say it's not their fault. But by the same token she is assigning adults responsibility for their own lives: if your life is not going well, stop moaning that it's all your parents' fault. She is rescuing mothers from fatuous theories that blame them for every misfortune that befalls their children, and from the censorious know-it-alls who make them feel like ogres if they slip out of the house to work or skip a reading of Goodnight Moon. And the theory assigns us all a collective responsibility for the health of the neighborhoods and culture in which peer groups are embedded.

[k8731] Childrearing is above all an ethical responsibility. It is not OK for parents to beat, humiliate, deprive, or neglect their children, because those are awful things for a big strong person to do to a small helpless one. As Harris writes, "We may not hold their tomorrows in our hands but we surely hold their todays, and we have the power to make their todays very miserable."

[k8740] As Harris puts it, "If you don't think the moral imperative is a good enough reason to be nice to your kid, try this one: Be nice to your kid when he's young so that he will be nice to you when you're old."

[k9098] Though moral sophistication requires an appreciation of history and cultural diversity, there is no reason to think that the elite arts are a particularly good way to instill it compared with middlebrow realistic fiction or traditional education. The plain fact is that there are no obvious moral consequences to how people entertain themselves in their leisure time. The conviction that artists and connoisseurs are morally advanced is a cognitive illusion, arising from the fact that our circuitry for morality is cross-wired with our circuitry for status (see Chapter 15). As the critic George Steiner has pointed out, "We know that a man can read Goethe or Rilke in the evening, that he can play Bach and Schubert, and go to his day's work at Auschwitz in the morning." Conversely there must be many unlettered people who give blood, risk their lives as volunteer firefighters, or adopt handicapped children, but whose opinion of modern art is "My four-year-old daughter could have done that." The moral and political track record of modernist artists is nothing to be proud of. Some were despicable in the conduct of their personal lives, and many embraced fascism or Stalinism.