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Speaker's Footnotes

Relevant notes and citations provided to TED by Tali Sharot.

  • 00:44

    Neil D. Weinstein, "Unrealistic optimism about future life events," Journal of Personality and Social Psychology, 1980

    The concept of unrealistic optimism can be traced back to Descartes as well as the German polymath Gottfried Wilhelm Leibniz, who notably held that we live in "the best of all possible worlds." Voltaire famously ridiculed Leibniz’s theory in his Candide, wherein Dr. Pangloss contemplates human suffering and misfortune only to assert that all is for the best!

    The social psychologist Neil Weinstein is credited for first demonstrating the phenomenon empirically.

  • 00:44

    Tali Sharot, The Optimism Bias, Vintage Books, 2012

    After Weinstein first showed empirical evidence for the concept of unrealistic optimism in 1980, my colleagues and I then unveiled neural and cognitive mechanisms that give rise to the optimism bias.

  • 01:00

    Lynn A. Baker and Robert E. Emery, "When every relationship is above average," Law and Human Behavior, August 1993

  • 03:50

    Jonathon D. Brown, "Evaluations of self and others: Self-enhancement biases in social judgments," Social Cognition, 1986

  • 04:06

    Christina Moutsiana et al., "Human development of the ability to learn from bad news," PNAS, 2013

  • 04:06

    Mariellen Fischer and Harold Leitenberg, "Optimism and pessimism in elementary school-aged children," Child Development, Februrary 1986

  • 04:06

    Rumana Chowdhury et al., "Optimistic update bias increases in older age," Psychological Medicine, November 2013

  • 04:06

    Edward C. Chang, "Cultural Influences on Optimism and Pessimism: Differences in Western and Eastern Construals of the Self," Optimism & Pessimism, Edward C. Chang (Editor), American Psychological Association, 2001

  • 04:36

    Barry Schwartz: The paradox of choice, TEDGlobal 2005

    See for example this brilliant and insightful TED Talk by Barry Schwartz.

  • 05:25

    Margaret A. Marshall and Jonathon D. Brown, "Emotional reactions to achievement outcomes: Is it really best to expect the worst?," Cognition and Emotion, 2006

  • 05:39

    George Loewenstein and Jon Elster (Editors), Choice over Time, Russell Sage Foundation, 1992

  • 07:35

    Maurice L. Farber, "Time-perspective and feeling-tone: A study in the perception of the days," Journal of Psychology, 1953

  • 07:44

    Daniel R. Strunk et al., "Depressive symptoms are associated with unrealistic negative predictions of future life events," Behaviour Research and Therapy, 2006

  • 07:55

    Shelley E. Taylor et al., "Psychological resources, positive illusions and health," American Psychologist, January 2000

  • 08:43

    Michael E. Scheier and Charles S. Carver, "Dispositional optimism and physical well-being: The influence of generalized outcome expectancies on health," Journal of Personality, June 1987

  • 08:50

    Michael Scheier et al., "Dispositional optimism and recovery from coronary artery bypass surgery," Journal of Personality and Social Psychology, December 1989

  • 08:50

    Jonathon D. Brown and Margaret A. Marshall, "Great expectations: Optimism and pessimism in achievement settings," Optimism & Pessimism, Edward C. Chang (Editor), American Psychological Association, 2001

  • 10:36

    Tali Sharot et al., "How unrealistic optimism is maintained in the face of reality," Nature Neuroscience, October 9, 2011

    I would like to clarify a common misunderstanding that comes up if people do not read our original Nature Neuroscience paper (which I urge you to do if you really want to understand the specifics of this study). Each participant in the study was asked to estimate their likelihood of experiencing 80 different negative events. While it is certainly possible that, for example, a participant (or even most participants) is less likely to suffer a specific illness than the average, this study is not about people’s perceptions of their vulnerability per se (and in that sense it is very different from past studies of the optimism bias). Rather, we study how people update these perceptions. We find that people alter their beliefs more when they receive information that is better than expected, rather than worse. This finding cannot be explained by whether you are in fact more or less likely to suffer these events or by whether the information I give you is accurate for you (because if you believe it was not accurate you should not update your beliefs at all, not even when you get good information). We have since replicated these findings in almost 1,000 individuals across the world in at least 10 independent studies using different designs of our task.

  • 12:42

    Tali Sharot et al., "How unrealistic optimism is maintained in the face of reality," Nature Neuroscience, October 9, 2011

    It is important to note that the colored clusters in the brain images do not represent greater brain activity. Rather, the colored regions show you areas in the brain where the amount of activity on each of the 80 trials is correlated with how good or bad information is relative to your expectations. In other words, these are regions where we think neuronal activity represents accurate computations that are needed to alter beliefs. You can have lots of activity in your brain when you get bad news, but that activity may be noisy, rather than a clear signal that relates to the information you were given.

    Another misconception is that these findings suggest that the inferior frontal gyrus (IFG) is solely responsible for optimism. This is not the case. First, we have shown that the IFG works in concert with many other regions. Second, optimism is a multifaceted concept. Here, we are only looking at one function that is related to optimism (how you learn about probabilities). There are other important functions that give rise to optimism that I did not have time to cover in 18 minutes (like imagination and memory).

  • 13:05

    Tali Sharot et al., "Selectively altering belief formation in the human brain," PNAS, 2012

    There were 30 participants in this study.

  • 15:15

    Manju Puri and David T. Robinson, "Optimism and economic choice," Journal of Financial Economics, October 2007