Publications

While appeals to gods and spirits are ubiquitous throughout human societies past and present, deities' postulated concerns vary across populations. How does the content of beliefs about and appeals to gods vary across groups, and what accounts for this variation? With particular emphasis on locally important deities, we develop a novel cultural evolutionary account that includes a set of predictive criteria for what deities will be associated with in various socioecological contexts. We then apply these criteria in an analysis of individual-level ethnographic free-list data on what pleases and angers locally relevant deities from eight diverse societies. We conclude with a discussion of how alternative approaches to cross-cultural variation in god beliefs and appeals fare against our findings and close by considering some key implications of our methods and findings for the cognitive and evolutionary study of religion.

Why did people across the world and throughout history believe that dreams can foretell what will occur in the future? In this paper, I attempt to answer this question within a cultural evolutionary framework by emphasizing the cognitive aspect of dream interpretation; namely, the fact that dreams were often viewed as significant and interpretable has to do with various psychological and social factors that influence how people obtain and process information regarding the validity of dream interpretation as a technique. Through a comprehensive analysis of a large dataset of dream occurrences in the official Chinese historical records, I argue that the ubiquity and persistence of dream interpretation have a strong empirical component (predictively accurate dream cases), which is particularly vulnerable to transmission errors and biases. The overwhelmingly successful records of dream prediction in transmitted texts, I suggest, is largely due to the fabrication and retrospective inference of past dreams, as well as the under-reporting of predictive failures. These “positive data” then reinforce individuals’ confidence in the predictive power of dreams. I finally show a potential decline of the popularity of dream interpretation in traditional China and offer a few suggestive explanations drawing on the unique characteristics of oneiromancy compared to other divination techniques.

e propose that humans may not meaningfully retain high-variance environmental feedback, a behavior that likely evolved in a past environment with unfavorable fitness tradeoffs from overcommitting attention. We argue that in such settings, humans instead rely on an innate estimate of future payoffs optimized for their evolutionary past of cultural learning: learning from knowledge taught by fellow group members, rather than from the environmental feedback itself. A veridical decision-theoretic model of this evolutionary past can help explain several puzzles of human behavior: (a) the hard-easy effect, the overconfidence (respectively, underconfidence) of one’s estimate of her ability in a difficult task (respectively, easy task); (b) underinference, the persistence of the aforementioned flawed belief in the face of evidence to the contrary; (c) the non-monotonicity of confidence with respect to the level of experience; (d) persistent vulnerability to charlatans; and (e) the situational effectiveness of marginal educational interventions. This finding corroborates the thesis [1, 2] that dual inheritance theory is an ideal candidate to be a cumulative theoretical framework for the psychological sciences. Our evolutionary theory and its predictions also have foundational policy implications, particularly for education.