The Optimism Bias

The Optimism Bias

Prologue

A Glass Forever Half Full?

I would have liked to tell you that my work on optimism grew out of a keen interest in the positive side of human nature. That would be a pleasant story: “A Cognitive Neuroscientist in Search of the Biological Basis of Our Hopeful Souls.” Pleasant but, unfortunately, untrue. I stumbled upon the optimism bias quite by accident while investigating people’s memories of the largest terrorist attack of our time. Back then, my scientific interests inclined more to the dark side: My principal research had been aimed at understanding how traumatic events shape our memories. I was interested in how the brain tricks us into believing that our recollections of exceptionally emotional events, such as the occurrences of September 11, 2001, are as accurate as a videotape, even when we are utterly mistaken.

I had been conducting research at New York University for over a year when American Airlines Flight 11 and United Flight 175 were flown into the World Trade Center at 430 miles per hour. Shock, confusion, and fear were the common responses on the street. Such forceful emotions are exactly the sort of reactions that will generate unusually vivid memories, ones that are reluctant to fade away. These are commonly referred to as “flashbulb memories” because of their sharp-edged, picturelike qualities. In chapter 9, I tell the story of flashbulb memories—how we remember unexpected arousing events and how the structures deep in our brain “Photoshop” these images, adding contrast, enhancing resolution, inserting and deleting details.

I was puzzled: Why had our brains developed a mechanism that would create highly vivid memories that were not necessarily accurate? Around the time my colleagues and I published our scientific investigation of memories of 9/11, a group of researchers at Harvard University proposed an intriguing answer. The neural system responsible for recollecting episodes from our past might not have been developed for that purpose at all. Rather, the core function of this system, which many had believed evolved for memory, may, in fact, be to imagine the future.

Brain-imaging studies show that the same brain structures that are engaged when we recollect our past are called upon when we think of the future. These two fundamental human thought activities rely on the same brain mechanisms; they draw on similar information and underlying processes.

Excerpted from The Optimism Bias by Tali Sharot. Copyright © 2011 by Tali Sharot. Excerpted by permission of Pantheon, a division of Random House, Inc. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.