Gut Feelings: The Intelligence Of The Unconscious

Gut Feelings Gut Feelings THE INTELLIGENCE OF THE UNCONSCIOUS GERD GIGERENZER VIKING VIKING Published by the Penguin Group Penguin Group (USA) Inc., 375 Hudson Street, New York, New York 10014, U.S.A. Penguin Group (Canada), 90 Eglinton Avenue East, Suite 700, Toronto, Ontario, Canada M4P 2Y3 (a division of Pearson Penguin Canada Inc.) Penguin Books Ltd, 80 Strand, London WC2R 0RL, England Penguin Ireland, 25 St. Stephen’s Green, Dublin 2, Ireland (a division of Penguin Books Ltd) Penguin Books Australia Ltd, 250 Camberwell Road, Camberwell, Victoria 3124, Australia (a division of Pearson Australia Group Pty Ltd) Penguin Books India Pvt Ltd, 11 Community Centre, Panchsheel Park, New Delhi—110 017, India Penguin Group (NZ), 67 Apollo Drive, Mairangi Bay, Auckland 1311, New Zealand (a division of Pearson New Zealand Ltd) Penguin Books (South Africa) (Pty) Ltd, 24 Sturdee Avenue, Rosebank, Johannesburg 2196, South Africa Penguin Books Ltd, Registered Offices: 80 Strand, London WC2R 0RL, England First published in 2007 by Viking Penguin, a member of Penguin Group (USA) Inc. Copyright © Gerd Gigerenzer, 2007 All rights reserved Illustrations by Jurgen Rossbach LIBRARY OF CONGRESS CATALOGING IN PUBLICATION DATA Gigerenzer, Gerd. Gut feelings : the intelligence of the unconscious / Gerd Gigerenzer. p. cm. Includes bibliographical references and index. ISBN: 978-1-1012-0241-8 1. Intuition. I. Title. BF315.5.G54 2007 153.4'4—dc22 2006052810 Without limiting the rights under copyright reserved above, no part of this publication may be reproduced, stored in or introduced into a retrieval system, or transmitted, in any form or by any means (electronic, mechanical, photocopying, recording, or otherwise), without the prior written permission of both the copyright owner and the above publisher of this book. The scanning, uploading, and distribution of this book via the Internet or via any other means without the permission of the publisher is illegal and punishable by law. Please purchase only authorized electronic editions and do not participate in or encourage electronic piracy of copyrightable materials. Your support of the author’s rights is appreciated. In affectionate memory of my mother and her courage, humor, and patience CONTENTS PART 1:UNCONSCIOUS INTELLIGENCE 1. Gut Feelings 2. Less Is (Sometimes) More 3. How Intuition Works 4. Evolved Brains 5. Adapted Minds 6. Why Good Intuitions Shouldn’t Be Logical PART 2:GUT FEELINGS IN ACTION 7. Ever Heard Of…? 8. One Good Reason Is Enough 9. Less Is More in Health Care 10. Moral Behavior 11. Social Instincts Acknowledgments Notes References Index We know more than we can tell. —Michael Polanyi Part 1 UNCONSCIOUS INTELLIGENCE The heart has its reasons of which reason knows nothing. —Blaise Pascal 1 GUT FEELINGS We think of intelligence as a deliberate, conscious activity guided by the laws of logic. Yet much of our mental life is unconscious, based on processes alien to logic: gut feelings, or intuitions. We have intuitions about sports, friends, which toothpaste to buy, and other dangerous things. We fall in love, and we sense that the Dow Jones will go up. This book asks: Where do these feelings come from? How do we know? Can following your gut feelings lead to some of the best decisions? It seems naive, even ludicrous, to think so. For decades, books on rational decision making, as well as consulting firms, have preached “look before you leap” and “analyze before you act.” Pay attention. Be reflective, deliberate, and analytic. Survey all alternatives, list all pros and cons, and carefully weigh their utilities by their probabilities, preferably with the aid of a fancy statistical