While forming and updating beliefs about future life outcomes, people tend to consider good news and to disregard bad news. This tendency is supposed to support the optimism bias. Whether this learning bias is specific to "high-level" abstract belief update or a particular expression of a more general "low-level" reinforcement learning process is unknown. Here we report evidence in favor of the second hypothesis. In a simple instrumental learning task, participants incorporated better-than-expected outcomes at a higher rate compared to worse-than-expected ones. In addition, functional imaging indicated that inter-individual difference in the expression of optimistic update corresponds to enhanced prediction error signaling in the reward circuitry. Our results constitute a new step in the understanding of the genesis of optimism bias at the neurocomputational level..

While forming and updating beliefs about future life outcomes, people tend to consider good news and to disregard bad news. This tendency is supposed to support the optimism bias. Whether learning bias is specific to "high-level" abstract belief update or a particular expression of a more general "low-level" reinforcement learning process is unknown. Here we report evidence in favor of the second hypothesis. In a simple instrumental learning task, participants incorporated worse-than-expected outcomes at a lower rate compared to better-than-expected ones. This asymmetry was correlated across subjects with standard measure of dispositional optimism. Multimodal imaging indicated that inter-individual variability in the expression of asymmetric update relies on the dorsomedial prefrontal cortex at both morphological and functional levels. Our results constitute a new step in the understanding of the genesis of optimism bias at the neurocomputational level.

We examined lay perceptions of the recent financial and economic crisis through 1707 questionnaires, administered via internet, to a varied group of volunteers in a range of countries: France, the US, Russia, Germany, Israel, and sub-Saharan Africa. Respondents graded the contribution of a large number of possible factors to the crisis, and answered several complementary questions. We were able to identify two major conceptions, one seeing the economy as comprised of individuals, with failings of moral or cognitive character, and the other seeing the economy as a complex system, endowed with some resilience, functioning in cycles. Support for the former view was stronger than for the latter. Several demographic variables were found to affect these perspectives significantly, including SES, economic training, religious beliefs, and the extent to which the respondent was personally affected by the crisis.