`Not another book on nature and nurture! Are there really people out there who still believe that the mind is a blank slate? Isn't it obvious to anyone with more than one child, to anyone who has been in a heterosexual relationship, or to anyone who has noticed that children learn language but house pets don't, that people are born with certain talents and temperaments? Haven't we all moved beyond the simplistic dichotomy between heredity and environment and realized that all behavior comes out of an interaction between the two?`
This is the kind of reaction I got from colleagues when I explained my plans for this book. At first glance the reaction is not unreasonable. Maybe nature versus nurture is a dead issue. Anyone familiar with current writings on mind and behavior has seen claims to the middle ground like these:
If the reader is now convinced that either the genetic or environmental explanation has won out to the exclusion of the other, we have not done a sufficiently good job of presenting one side or the other. It seems highly likely to us that both genes and environment have something to do with this issue. What might the mix be? We are resolutely agnostic on that issue; as far as we can determine, the evidence does not yet justify an estimate.
This is not going to be one of those books that says everything is genetic: it isn't. The environment is just as important as the genes. The things children experience while they are growing up are just as important as the things they are born with.
Even when a behavior is heritable, an individual's behavior is still a product of development, and thus it has a causal environmental
component___ The modern understanding of how phenotypes are inherited through the replication of both genetic and environmental conditions suggests that... cultural traditions—behaviors copied by children from their parents—are likely to be crucial.If you think these are innocuous compromises that show that everyone has outgrown the nature-nurture debate, think again. The quotations come, in fact, from three of the most incendiary books of the last decade. The first is from The Bell Curve by Richard Herrnstein and Charles Murray, who argue that the difference in average IQ scores between American blacks and American whites has both genetic and environmental causes.1 The second is from The Nurture Assumption by Judith Rich Harris, who argues that children's personalities are shaped by their genes as well as by their environments, so similarities between children and their parents may come from their shared genes and not just from the effects of parenting.2 The third is from A Natural History of Rape by Randy Thornhill and Craig Palmer, who argue that rape is not simply a product of culture but also has roots in the nature of men's sexuality.3 For invoking nurture and nature, not nurture alone, these authors have been picketed, shouted down, subjected to searing invective in the press, even denounced in Congress. Others expressing such opinions have been censored, assaulted, or threatened with criminal prosecution.4
The idea that nature and nurture interact to shape some part of the mind might turn out to be wrong, but it is not wishy-washy or unexceptionable, even in the twenty-first century, thousands of years after the issue was framed. When it comes to explaining human thought and behavior, the possibility that heredity plays any role at all still has the power to shock. To acknowledge human nature, many think, is to endorse racism, sexism, war, greed, genocide, nihilism, reactionary politics, and neglect of children and the disadvantaged. Any claim that the mind has an innate organization strikes people not as a hypothesis that might be incorrect but as a thought it is immoral to think.
This book is about the moral, emotional, and political colorings of the concept of human nature in modern life. I will retrace the history that led people to see human nature as a dangerous idea, and I will try to unsnarl the moral and political rat's nests that have entangled the idea along the way. Though no book on human nature can hope to be uncontroversial, I did not write it to be yet another `explosive` book, as dust jackets tend to say. I am not, as many people assume, countering an extreme `nurture` position with an extreme `nature` position, with the truth lying somewhere in between. In some cases, an extreme environmentalist explanation is correct: which language you speak is an obvious example, and differences among races and ethnic groups in test scores may be another. In other cases, such as certain inherited neurological disorders, an extreme hereditarian explanation is correct. In most cases the correct explanation will invoke a complex interaction between heredity and environment: culture is crucial, but culture could not exist without mental faculties that allow humans to create and learn culture to begin with. My goal in this book is not to argue that genes are everything and culture is nothing— no one believes that—but to explore why the extreme position (that culture is everything) is so often seen as moderate, and the moderate position is seen as extreme.
Nor does acknowledging human nature have the political implications so many fear. It does not, for example, require one to abandon feminism, or to accept current levels of inequality or violence, or to treat morality as a fiction. For the most part I will try not to advocate particular policies or to advance the agenda of the political left or right. I believe that controversies about policy almost always involve tradeoffs between competing values, and that science is equipped to identify the tradeoffs but not to resolve them. Many of these tradeoffs, I will show, arise from features of human nature, and by clarifying them I hope to make our collective choices, whatever they are, better informed. If I am an advocate, it is for discoveries about human nature that have been ignored or suppressed in modern discussions of human affairs.
Why is it important to sort this all out? The refusal to acknowledge human nature is like the Victorians' embarrassment about sex, only worse: it distorts our science and scholarship, our public discourse, and our day-to-day lives. Logicians tell us that a single contradiction can corrupt a set of statements and allow falsehoods to proliferate through it. The dogma that human nature does not exist, in the face of evidence from science and common sense that it does, is just such a corrupting influence.
First, the doctrine that the mind is a blank slate has distorted the study of human beings, and thus the public and private decisions that are guided by that research. Many policies on parenting, for example, are inspired by research that finds a correlation between the behavior of parents and the behavior of children. Loving parents have confident children, authoritative parents (neither too permissive nor too punitive) have well-behaved children, parents who talk to their children have children with better language skills, and so on. Everyone concludes that to grow the best children, parents must be loving, authoritative, and talkative, and if children don't turn put well it must be the parents' fault. But the conclusions depend on the belief that children are blank slates. Parents, remember, provide their children with genes, not just a home environment. The correlations between parents and children may be telling us only that the same genes that make adults loving, authoritative, and talkative make their children self-confident, well-behaved, and articulate. Until the studies are redone with adopted children (who get only their environment, not their genes, from their parents), the data are compatible with the possibility that genes make all the difference, the possibility that parenting makes all the difference, or anything in between. Yet in almost every instance, the most extreme position—that parents are everything—is the only one researchers entertain.
The taboo on human nature has not just put blinkers on researchers but turned any discussion of it into a heresy that must be stamped out. Many writers are so desperate to discredit any suggestion of an innate human constitution that they have thrown logic and civility out the window. Elementary distinctions—`some` versus `all,` `probable` versus `always,` `is` versus `ought`—are eagerly flouted to paint human nature as an extremist doctrine and thereby steer readers away from it. The analysis of ideas is commonly replaced by political smears and personal attacks. This poisoning of the intellectual atmosphere has left us unequipped to analyze pressing issues about human nature just as new scientific discoveries are making them acute.
The denial of human nature has spread beyond the academy and has led to a disconnect between intellectual life and common sense. I first had the idea of writing this book when I started a collection of astonishing claims from pundits and social critics about the malleability of the human psyche: that little boys quarrel and fight because they are encouraged to do so; that children enjoy sweets because their parents use them as a reward for eating vegetables; that teenagers get the idea to compete in looks and fashion from spelling bees and academic prizes; that men think the goal of sex is an orgasm because of the way they were socialized. The problem is not just that these claims are preposterous but that the writers did not acknowledge they were saying things that common sense might call into question. This is the mentality of a cult, in which fantastical beliefs are flaunted as proof of one's piety. That mentality cannot coexist with an esteem for the truth, and I believe it is responsible for some of the unfortunate trends in recent intellectual life. One trend is a stated contempt among many scholars for the concepts of truth, logic, and evidence. Another is a hypocritical divide between what intellectuals say in public and what they really believe. A third is the inevitable reaction: a culture of `politically incorrect` shock jocks who revel in anti-intellectualism and bigotry, emboldened by the knowledge that the intellectual establishment has forfeited claims to credibility in the eyes of the public.
Finally, the denial of human nature has not just corrupted the world of critics and intellectuals but has done harm to the lives of real people. The theory that parents can mold their children like clay has inflicted childrearing regimes on parents that are unnatural and sometimes cruel. It has distorted the choices faced by mothers as they try to balance their lives, and multiplied the anguish of parents whose children haven't turned out the way they hoped. The belief that human tastes are reversible cultural preferences has led social planners to write off people's enjoyment of ornament, natural light, and human scale and force millions of people to live in drab cement boxes. The romantic notion that all evil is a product of society has justified the release of dangerous psychopaths who promptly murdered innocent people. And the conviction that humanity could be reshaped by massive social engineering projects led to some of the greatest atrocities in history
Though many of my arguments will be coolly analytical—that an acknowledgment of human nature does not, logically speaking, imply the negative outcomes so many people fear—I will not try to hide my belief that they have a positive thrust as well. `Man will become better when you show him what he is like,` wrote Chekhov, and so the new sciences of human nature can help lead the way to a realistic, biologically informed humanism. They expose the psychological unity of our species beneath the superficial differences of physical appearance and parochial culture. They make us appreciate the wondrous complexity of the human mind, which we are apt to take for granted precisely because it works so wei. They identify the moral intuitions that we can put to work in improving our lot. They promise a naturalness in human relationships, encouraging us to treat people in terms of how they do feel rather than how some theory says they ought to feel. They offer a touchstone by which we can identify suffering and oppression wherever they occur, unmasking the rationalizations of the powerful. They give us a way to see through the designs of self-appointed social reformers who would liberate us from our pleasures. They renew our appreciation for the achievements of democracy and of the rule of law. And they enhance the insights of artists and philosophers who have reflected on the human condition for millennia.
An honest discussion of human nature has never been more timely. Throughout the twentieth century, many intellectuals tried to rest principles of decency on fragile factual claims such as that human beings are biologically indistinguishable, harbor no ignoble motives, and are utterly free in their ability to make choices. These claims are now being called into question by discoveries in the sciences of mind, brain, genes, and evolution. If nothing else, the completion of the Human Genome Project, with its promise of an unprecedented understanding of the genetic roots of the intellect and the emotions, should serve as a wake-up call. The new scientific challenge to the denial of human nature leaves us with a challenge. If we are not to abandon values such as peace and equality, or our commitments to science and truth, then we must pry these values away from claims about our psychological makeup that are vulnerable to being proven false.
This book is for people who wonder where the taboo against human nature came from and who are willing to explore whether the challenges to the taboo are truly dangerous or jiist unfamiliar. It is for those who are curious about the emerging portrait of our species and curious about the legitimate criticisms of that portrait. It is for those who suspect that the taboo against human nature has left us playing without a full deck as we deal with the pressing issues confronting us. And it is for those who recognize that the sciences of mind, brain, genes, and evolution are permanently changing our view of ourselves and wonder whether the values we hold precious will wither, survive, or (as I will argue) be enhanced.
It is a pleasure to acknowledge the friends and colleagues who improved this book in innumerable ways. Helena Cronin, Judith Rich Harris, Geoffrey Miller, Orlando Patterson, and Donald Symons offered deep and insightful analyses of every aspect, and I can only hope that the final version is worthy of their wisdom. I profited as well from invaluable comments by Ned Block, David Buss, Nazli Choucri, Leda Cosmides, Denis Dutton, Michael Gazzaniga, David Geary, George Graham, Paul Gross, Marc Hauser, Owen Jones, David Kemmerer, David Lykken, Gary Marcus, Roslyn Pinker, Robert Plomin, James Rachels, Thomas Sowell, John Tooby, Margo Wilson, and William Zimmerman. My thanks also go to the colleagues who reviewed chapters in their areas of expertise: Josh Cohen, Richard Dawkins, Ronald Green, Nancy Kanwisher, Lawrence Katz, Glenn Loury, Pauline Maier, Anita Patterson, Mriganka Sur, and Milton J. Wilkinson.
I thank many others who graciously responded to requests for information or offered suggestions that found their way into the book: Mahzarin Ba-naji, Chris Bertram, Howard Bloom, Thomas Bouchard, Brian Boyd, Donald Brown, Jennifer Campbell, Rebecca Cann, Susan Carey, Napoleon Chagnon, Martin Daly, Irven DeVore, Dave Evans, Jonathan Freedman, Jennifer Ganger, Howard Gardner, Tamar Gendler, Adam Gopnik, Ed Hagen, David Housman, Tony Ingram, William Irons, Christopher Jencks, Henry Jenkins, Jim Johnson, Erica Jong, Douglas Kenrick, Samuel Jay Keyser, Stephen Kosslyn, Robert KUrzban, George Lakoff, Eric Lander, Loren Lomasky, Martha Nussbaum, Mary Parlee, Larry Squire, Wendy Steiner, Randy Thornhill, James Watson, Torsten Wiesel, and Robert Wright.
The themes of this book were first presented at forums whose hosts and audiences provided vital feedback. They include the Center for Bioethics at the University of Pennsylvania; the Cognition, Brain, and Art Symposium at the Getty Research Institute; the Developmental Behavior Genetics conference at the University of Pittsburgh; the Human Behavior and Evolution Society; the Humane Leadership Project at the University of Pennsylvania; the Institute on Race and Social Division at Boston University; the School of Humanities, Arts, and Social Sciences at MIT; the Neurosciences Research Program at the Neu-rosciences Institute; the Positive Psychology Summit; the Society for Evolutionary Analysis in Lawi and the Tanner Lectures on Human Values at Yale University.
I am happy to acknowledge the superb environment for teaching and inquiry at the Massachusetts Institute of Technology, and the support of Mriganka Sur, head of the Department of Brain and Cognitive Sciences, Robert Silbey, dean of the School of Science, Charles Vest, president of MIT, and many colleagues and students. John Bearley, the librarian of the Teuber Library, tracked down scholarly materials and answers to questions no matter how obscure. I also gratefully acknowledge the financial support of the MIT Mac Vicar Faculty Fellows program and the Peter de Florez chair. My research on language is supported by NIH Grant HD18381.
Wendy Wolf at Viking Penguin and Stefan McGrath at Penguin Books provided excellent advice and welcome good cheer. I thank them and my agents, John Brockman and Katinka Matson, for their efforts on behalf of the book. I am delighted that Katya Rice agreed to copy-edit this book, our fifth collaboration.
My heartfelt appreciation goes to my family, the Pinkers, Boodmans, and Subbiah-Adamses, for their love and support. Special thanks to my wife, Ilave-nil Subbiah, for her wise advice and loving encouragement.
This book is dedicated to four people who have been dear friends and profound influences: Donald Symons, Judith Rich Harris, Leda Cosmides, and John Tooby.