Market exposure and human morality.

According to evolutionary theories, markets may foster an internalized and universalist prosociality because it supports market-based cooperation. This paper uses the cultural folklore of 943 pre-industrial ethnolinguistic groups to show that a society's degree of market interactions, proxied by the presence of intercommunity trade and money, is associated with the cultural salience of (1) prosocial behaviour, (2) interpersonal trust, (3) universalist moral values and (4) moral emotions of guilt, shame and anger. To provide tentative evidence that a part of this correlation reflects a causal effect of market interactions, the analysis leverages both fine-grained geographic variation across neighbouring historical societies and plausibly exogenous variation in the presence of markets that arises through proximity to historical trade routes or the local degree of ecological diversity. The results suggest that the coevolutionary process involving markets and morality partly consists of economic markets shaping a moral system of a universalist and internalized prosociality.

Confidence and central tendency in perceptual judgment.

This paper theoretically and empirically investigates the role of noisy cognition in perceptual judgment, focusing on the central tendency effect: the well-known empirical regularity that perceptual judgments are biased towards the center of the stimulus distribution. Based on a formal Bayesian framework, we generate predictions about the relationships between subjective confidence, central tendency, and response variability. Specifically, our model clarifies that lower subjective confidence as a measure of posterior uncertainty about a judgment should predict (i) a lower sensitivity of magnitude estimates to objective stimuli; (ii) a higher sensitivity to the mean of the stimulus distribution; (iii) a stronger central tendency effect at higher stimulus magnitudes; and (iv) higher response variability. To test these predictions, we collect a large-scale experimental data set and additionally re-analyze perceptual judgment data from several previous experiments. Across data sets, subjective confidence is strongly predictive of the central tendency effect and response variability, both correlationally and when we exogenously manipulate the magnitude of sensory noise. Our results are consistent with (but not necessarily uniquely explained by) Bayesian models of confidence and the central tendency.