How We Decide

How We Decide Jonah Lehrer Table of Contents Title Page Table of Contents ... Copyright Dedication Contents Epigraph Introduction 1. The Quarterback in the Pocket 2. The Predictions of Dopamine 3. Fooled by a Feeling 4. The Uses of Reason 5. Choking on Thought 6. The Moral Mind 7. The Brain Is an Argument 8. The Poker Hand Coda ... Acknowledgments Notes Bibliography Index Footnotes HOUGHTON MIFFLIN HARCOURT BOSTON • NEW YORK 2009 Copyright © 2009 by Jonah Lehrer ALL RIGHTS RESERVED For information about permission to reproduce selections from this book, write to Permissions, Houghton Mifflin Harcourt Publishing Company, 215 Park Avenue South, New York, New York 10003. www.hmhbooks.com Library of Congress Cataloging-in-Publication Data Lehrer, Jonah. How we decide / Jonah Lehrer. p. cm. Includes bibliographical references and index. ISBN 978-0-618-62011-1 1. Decision making. I. Title. BF448.L45 2009 153.8'3—dc22 2008036769 Printed in the United States of America Book design by Victoria Hartman DOC 10 9 8 7 6 5 4 3 2 1 To my siblings, Eli, Rachel, and Leah Contents INTRODUCTION [>] 1. The Quarterback in the Pocket [>] 2. The Predictions of Dopamine [>] 3. Fooled by a Feeling [>] 4. The Uses of Reason [>] 5. Choking on Thought [>] 6. The Moral Mind [>] 7. The Brain Is an Argument [>] 8. The Poker Hand [>] Coda [>] ACKNOWLEDGMENTS NOTES [>] BIBLIOGRAPHY INDEX [>] [>] [>] Who knows what I want to do? Who knows what anyone wants to do? How can you be sure about something like that? Isn't it all a question of brain chemistry, signals going back and forth, electrical energy in the cortex? How do you know whether something is really what you want to do or just some kind of nerve impulse in the brain? Some minor little activity takes place somewhere in this unimportant place in one of the brain hemispheres and suddenly I want to go to Montana or I don't want to go to Montana. —DON DELILLO, White Noise Introduction I was flying a Boeing 737 into Tokyo Narita International Airport when the left engine caught on fire. We were at seven thousand feet, with the runway dead ahead and the skyscrapers shimmering in the distance. Within seconds, bells and horns were blaring inside the cockpit, warning me of multiple system failures. Red lights flashed all over the place. I tried to suppress my panic by focusing on the automated engine-fire checklist, which told me to cut off fuel and power to the affected areas. Then the plane began a steep bank. The evening sky turned sideways. I struggled to steer the plane straight. But I couldn't. The plane was impossible to fly. It swayed one way, I tried to pull her back to center, and then it swayed the other way. It was like wrestling with the atmosphere. Suddenly, I felt the shudder of a stall: the air was moving too slowly over the wings. The metal frame started to shriek and groan, the awful sound of steel giving way to physics. If I didn't find a way to increase my speed immediately, the plane would quickly surrender to the downward tug of gravity and I'd plunge into the city below. I didn't know what to do. If I increased the throttle, I might be able to gain altitude and speed, and then I could circle around the runway and try to stabilize the plane. But could my only remaining engine handle the climb by itself? Or would it fail under the strain? The other option was to steepen my descent in a desperate attempt to pick up speed; I'd fake a nosedive in order to avoid a real one. The downward momentum might let me avert the stall and steer the plane. Of course, I might instead be accelerating toward disaster. If I couldn't regain control, then the plane would fall into what pilots