DESIGN LI FE ALSO BY PATRICK BATESON The Behavioural and Physiological Effects of Culling Red Deer Perspectives in Ethology (edited with Peter H. Klopfer) Growing Points in Ethology (edited with Robert A. Hinde) Mate Choice (editor) The Domestic Cat: The Biology of its Behaviour (edited with Dennis C. Turner) The Development and Integration of Behaviour (editor) Behavioural Mechanisms in Evolutionary Perspective (edited with Montse Gomendio) ALSO BY PAUL MARTIN The Healing Mind: The Vital Links Between Brain and Behavior, Immunity and Disease Measuring Behaviour: An Introductory Guide (with Patrick Bateson) • SI 11 ora PatricR Batesol1 How Behavior and Personality Develop SIMON & SCHUSTER NEW YORK LONDON TORONTO SYDNEY SINGAPORE al1d Paul Martil1 1: "'4 SIMON & SCHUSTER Rocktfeller Center -.L.b 1230Avet1ue of tlteAmericas � Contents New York, NY 10020 Copyright © 2000 by Patrick Batesoll and Paul Martin All rights reserved, including the rigltt oj reproduction in whole or in part in any form. SIMON & SCHUSTER and colophon are registered trademarks oj Simon & Schuster, Inc. 1 Designed by Edith Fowler Mamifactured in the United States ojAmerica 10 9 8 7 6 5 4 3 2 THE DEVELOPMENTAL KITCHEN 9 • Design for 1 Library of Congress Cataloging-in-Publication Data Bateson, 2 P P G. (Paul Patrick Gordon) Design for a life: how beltavior and personality develop / Patrick Bateson and Paul Martin. p.cm. I"cludes bibliographical rtferences and illdex. 1. Nature and nurture. II. 1. THE SEVEN AGES 18 Players on the Stage • Parents, Offspring, and Conflict • Life in the JiV£Jmb • A Brave New JiV£Jrld • The Beginning of the End • They Tuck You Up • And Then the Lover • And Then the Justice • Last Scene of All Martill, Paul R. Title. BF341.B37 From Egg to Adult • "Nature" and "Nurture" a Life • The Developmental Menu 3 2000 155.2'34-dc21 99-086972 ISBN 0-684-86932-2 First published in the United Kingdom i" 1999, 4 by Jonatltan Cape 5 • THE SPARKS OF NATURE 42 The Family Face • Spirally Bound • Twins • What About the Environment? • Early Handling • Dear Octopus • Myopia and Music • How Much Nature, How Much Nurture? COOKING BEHAVIOR 62 The Great Blueprint Fallacy • Genes Make Proteins, Not Behavior • Niche-picking • A Picture of Differences • Little Emperors? • Rules for Changing the Rules • System and Synthesis P ROTEAN INSTINCTS Original Matter • The Universal Smile • The Stink of Instinct • A Little Dose of Judgment • Managing the Machine • A Well-designed Life • Flexible Structure 78 8 CONTENTS 6 ALTERNATIVE LIVES 100 The Developmental Jukebox • Forecasting the Weather • Growing People • Pubertal Precocity • Street Children • Different 7 • CHANCE AND CHOICE Darwin's Nose • Storm and Stress • VVhat's in a Name? Choice • How Much Free Will? • Tangled Threads 8 I • SENSITIVE PERIODS Vulnerable T imes • Something Nasty in the Woodshed • Learning to Speak • Learning to Sing • Closing Options Stamping In • Competitive Exclusion • Learning the Lessons 9 • 133 • MORNING SHOWS THE DAY Life Sentence • Wiping the Tapes? • More Than a Seed Staying on Track • Different Routes to the Same Place • The Strands of Continuity 10 117 154 The Developmental Kitchen What is the use of a new-born child? • ROOM 101 BENJAMIN FRANKLIN 167 Metamorphosis • From Elastic to Plastic • Breaking the Mold • Stress, Love, and Hormones • Long Live Change 11 • 12 • 13 • EVERYTHING TO PLAY FOR 182 Pointless Fun • Tom Sawyer's Fence • From Eton to Waterloo • Connecting the Unconnected • Roaming Freely FROM EGG TO ADULT How and why does each human grow up to be a unique indi­ vidual? What role do genes play in shaping behavior and personality? Are people's characters fixed early in life or can they change as adults? How does early experience affect sexual preferences? Why do SEX, BEAUTY, AND INCEST 198 It's Just It • Extravagant Ornaments • Some Strangeness in the Proportion • Striking the Balance • Cooking the Preferences • The Developmental Origins of Homosexuality • Serious Commitment • From Inbreeding Avoidance to Incest Taboos THIS STRANGE EVENTFUL HISTORY The One True Cause • The Evolution of Development • VVho Chooses, VVho Designs? • Building Clever Machines A Process Too Complicated to Explain? 219 children play? These are all questions about behavioral develop­ ment-the lifelong process of growth and change from conception to death, which is central to an understanding of human nature. Mter the microscope was invented in the late sixteenth century, people gazed with excitement at the structure of the fertilized egg and thought they could see dimly within it the makings of an adult. Some even saw a small person crouched inside the head of each human sperm-or, if their prejudices were different, inside the unfer­ • ACKNOWLEDGMENTS 233 PERMISSIONS 235 REFERENCES 237 FURTHER READING 253 INDEX 255 tilized egg. It seemed satisfYing to think of growing up as merely get­ ting larger. But the satisfaction was deeply misplaced. Most animals, including humans, do not just grow-they develop. Everybody is the product of development. The fertilized egg from which each person develops is barely visible to the eye. The adult human body consists of millions upon 1 2 DESIGN FOR A LIFE learning. So congenial was this opinion to Lenin that Pavlov's posi­ tion in the Soviet Union was thereafter protected, despite his not being a Communist. In 1950, long after Pavlov's death, a big govern­ THE DEVELOPMENTAL KiTCHEN 13 DESIGN FOR A LIFE The various stages of an individual's development, from concep­ ment-sponsored scientific congress devoted to his teaching was held tion through childhood, adolescence, parenthood (for most), and the in Moscow. The party line was that man could transcend heredity later years of maturity and senescence, are completely different, and and be controlled by education. A second prong in the same Stalinist the individual must function at least adequately during each of them. program was to enforce as dogma the view that all acquired charac­ Even though it is easy to think of exceptions where brain and behav­ ters were passed on to subsequent generations. Under the advocacy ior malfunction terribly, as in paranoid schizophrenia, much of what of this dogma by T. D. Lysenko in the late 1940s, Soviet genetics ef­ happens during the process of development looks as though it is well fectively ceased to exist. designed. The proposition that living organisms' bodies, brains, and One cynic commented that the "environmentalists seem to be­ behavior were adapted over the course of evolution to the conditions lieve that if cats gave birth in a stove, the result would be biscuits. " in which they lived is at least familiar to most nonbiologists. An Since then, the pendulum has swung a long way in the opposite di­ adaptation is a modification that makes the organism better suited to rection, and nowadays it sometimes seems as if almost any aspect of survive and reproduce in a particular environment-better suited, human behavior or physiology can be accounted for by genes alone. that is, than if it lacked the crucial feature. With increasing frequency the media report the discover y of a gene In the early part of the nineteenth century, the English theolo­ "for " some distinct human characteristic, such as learning foreign gian William Paley wrote incisively about the adaptations of biology. Natural Theology, Paley emphasized how different parts of languages, athletic prowess, or male promiscuity. In his book It is obvious that experience, education, and culture make a big the body relate to each other and contribute to the whole. He illus­ difference in how people behave, whatever their genetic inheritance. trated this by considering the various features of the mole: Yet behavioral and psychological development is frequently ex­ plained in terms of the exclusive importance of one set of factors, ei­ The strong short legs of that animal, the palmated feet ther genetic or environmental. Such firmly held opinions derive in armed with sharp nails, the pig-like nose, the teeth, the part from a style of advocacy common to most scientific debates. If velvet coat, the small external ear, the sagacious smell, Dr. Jones has overstated her case, then Professor Smith feels bound to the sunk protected eye, all conduce to the utilities or to the redress the balance by overstating the counterargument. The confu­ safety of its underground life. . . . The mole did not want sions are amplified because of the way in which scientists analyze de­ to look about it; nor would a large advanced eye have been velopmental processes. When somebody has conducted a clever easily defended from the annoyance to which the life of experiment demonstrating an important long-term influence on be­ the animal must constantly expose it. How indeed was the havior, he or she has good reason to feel pleased. It is easy to forget mole, working its way under ground, to guard its eyes at about all those other influences that they had contrived to keep con­ all? In order to meet this difficulty, the eyes are made stant or that play no systematic role. Consequently, debates about be­ scarcely larger than the head of a corking-pin; and these havioral and psychological development often degenerate into minute globules are sunk so deeply in the skull, and lie so sweeping assertions about the overriding importance of genes (stand­ sheltered within the velvet of its covering, as that any con­ ing in for "nature ") or the crucial significance of the environment traction of what may be called the eye-brows, not only (which then becomes "nurture "). closes up the apertures which lead to the eyes, but presents 1 4 15 DESIGN FOR A LIFE THE DEVELOPMENTAL KITCHEN a cushion, as it were, to any sharp or protruding substance propagation-let alone conscious ones. In Richard Dawkins's phrase: which might push against them. This aperture, even in its "The world became full of organisms that have what it takes to be­ ordinary state, is like a pin-hole in a piece of velvet, come ancestors. " scarcely pervious to loose particles of earth. Biologists have been properly warned not to write evolutionar y Observe then, in this structure, that which we call re­ accounts in which the past is seen as leading purposefully toward the lation. There is no natural connection between a small goal of the present blissful state of perfection. A clear distinction is sunk eye and shovel palmated foot. Palmated feet might necessarily and wisely drawn between the present-day utility (or have been joined with goggle eyes; or small eyes might function) of a biological process, structure, or behavior pattern and its have been joined with feet of any other form. What was it historical, evolutionary origins. Darwin noted, for example, that therefore which brought them together in the mole? That while the bony plates of the mammalian skull allow the young mam­ which brought together the barrel, the chain, and the cogs, mal an easier passage through the mother's birth canal, these same in a watch-design; and design, in both cases, inferred plates are also present in the mammals' egg-laying reptilian ancestors. from the relation which the parts bear to one another in Their original biological function clearly must have been different the prosecution of a common purpose. . . . In a word; the from their current function. 3 feet of the mole are made for digging; the neck, nose, eyes, The distinction between current function and historical evolu­ ears, and skin are peculiarly adapted to an underground tion is all the more necessary because current adaptations may result life; and this is what I call relation. from the experience of the individual during its lifetime. Human hands form calluses to protect against mechanical wear, and muscles Paley, who became a bishop, regarded the design he saw ever y­ where in nature as proof of the existence of God. These days few bi­ develop in response to the specific loads placed upon them during exercise. Behavior, in particular, becomes adapted to local conditions ologists would try to pin their religious faith on biological evidence, during the course of an individual's development, whether through and the design to which Paley referred would be attributed instead to learning by trial and error or through copying others. These are all the evolutionary mechanism that Charles Darwin called natural se­ examples of adaptations that are acquired during the lifetime of the lection. Darwin's theory of evolution by natural selection is univer­ individual, and they are clearly distinct from adaptations that are in­ sally accepted among scientists, even if arguments continue over the herited. "Design " in this book is used in its widest sense to denote details. Darwin proposed a three-stage cycle that starts with random adaptations, whatever their biological origins. variation in the form and behavior of individuals. In any given set of environmental conditions some individuals are better able to survive and reproduce than others because of their distinctive characteristics. The historical process of becoming adapted notches forward a step if make it resistant to the latest antibiotic. While all the others are killed by antibiotics, this one will survive and multiply rapidly. Before long, the world (or, at least, the hospital ward) is full of antibiotic-resistant bacteria. Darwinian evolution requires no unconscious motives for THE DEVELOPMENTAL MENU A young man who was contemplating a career as a chef visited a the factors that gave rise to those distinctive characteristics are inher­ country hotel that prided itself on using only the best locally grown ited in the course of reproduction. Suppose, for example, that an in­ produce. He was solemnly told that the only thing that matters in dividual bacterium happens to have heritable characteristics that good cooking is to ensure the ingredients are of high quality. The young man was not stupid, however, and felt this advice must be incomplete. T hen he consulted the celebrated chef of a fashionable urban restaurant and was told emphatically that what really matters is hav ing the right kitchen equipment and paying meticulous attention 1 6 DESIGN FOR A LIFE to the presentation of the food at the table: "You can make anything THE DEVELOPMENTAL KITCHEN 1 7 Undoubtedly, many important aspects of behavioral and psy­ look beautiful and taste marvelous." Our novice chef sensed that chological development do relate to the individual's future rather both his advisers had been claiming too much. Their prejudices were than current needs. Certain adaptations-such as play behavior­ compounded by self-righteousness when they heard about the views assist the developmental process of acquiring skills or knowledge of of the other. Though as yet unversed in the mysteries of cooking, the the social and physical environment, which will be needed in later young man realized intuitively that the ingredients of a meal and the life. Preparation for the future may make use of predictive informa­ way in which they are put together must both matter. He went on to tion about the environment that the individual will inhabit. The become a much better chef than either of his advisers. need to predict becomes especially important when the physical or The processes involved in behavioral and psychological devel­ social environment may take radically different forms, forcing indi­ opment have certain metaphorical similarities to cooking. Both the viduals to use quite different solutions according to the particular raw ingredients and the manner in which they are combined are im­ problems they face. The habitats in which humans may end up are portant. Timing also matters. In the cooking analogy, the raw ingre­ dramatically different from each other, some demanding physically dients represent the many genetic and environmental influences, and others demanding socially. Individuals are prepared in some mea­ while cooking represents the biological and psychological processes sure during their early development for the particular adult world of development. Nobody expects to find all the separate ingredients they will enter. represented as discrete, identifiable components in a souffle. Similarly, Inevitably, much of what we shall describe in this book reflects nobody should expect to find a simple correspondence between a common experience. We shall draw from time to time on the writ­ particular gene (or a particular experience) and particular aspects of ings of novelists and poets who have expressed themselves more an individual's behavior or personality. This point, which we hope memorably, amusingly, or imaginatively than we could ever-have will be obvious, is central to much of what we describe in this book. done. We hope that this interweaving of science and literature will "Man is born to live, not to prepare for life," wrote Boris Paster­ seem as natural to others as it did to us. When dealing with substance nak in Doctor Zhivago. The behavior seen at a particular stage of life may be part of the cooking process of development, but it may also serve a current need. Many attributes of a young, developing organ­ ism are adaptations to the environment it inhabits at that stage in its life. To become an adult, the young animal or child must obviously survive in the here and now. But some of what goes on in develop­ ment is also about preparing for the future, setting the menu for the life yet to come. This forward-looking aspect of development was expressed by Simone de Beauvoir in her autobiography: All through my childhood and my young days, my life had a distinct meaning: its goal and its motive was to reach the adult age. At twenty, living does not mean getting ready to be forty. Yet for my people and for me, my duty as a child and an adolescent consisted of forming the woman I was to be tomor row. rather than method, we believe that the wall built between the sci­ ences and the humanities is artificial and unhelpful-and nowhere more so than in the kitchen of human development.