Current Projects

The Origins of WEIRD Psychology, Government Effectiveness, and Economic Prosperity

CrossA growing body of research suggests that populations around the globe vary substantially along important psychological dimensions. Yet, efforts to understand the origins of this variation and its impact on economic outcomes have only just begun. Here, we explore the hypothesis that kin-based institutions are a key determinant of this psychological variation and that they have strong downstream impacts on the effectiveness of political and economic organizations. 

We’ll examine three questions. First, does the variation in kin-based institutions help account for extant psychological variation? Second, can differences in kin-based institutions, and in particular in Europe’s kinship systems, be traced back to the Medieval Christianity’s peculiar religious prohibitions? Third, have the differences in kin-based institutions influenced the effectiveness of political and economic institutions.

Methodologically, we plan to assemble and analyze new historical databases, comparative experimental data from diverse societies and genetic data (to infer kinship). In particular, our analysis of historical corpora will permit us to track psychological changes through space and over centuries. The proposed research holds the potential to profoundly impact how researchers in psychology, economics, and history tackle fundamental questions in their fields.


Identifying the Cultural Foundations of Human Cognition

Flynn EffectFormal education is often assumed to influence the content of our minds—what we know—but several new lines of evidence increasingly suggest that the effect of education runs far deeper: raising our cognitive abilities, increasing analytic thinking, empowering selfregulation, and improving executive function. In other words, schooling not only transmits knowledge, but shapes core aspects of our cognition and behavior. For this project, Helen Davis, postdoctoral researcher, will focus on time-sensitive natural-experiments in two rural, substance-based economies within Africa and South America to examine the longitudinal effects of schooling on cognitive performance, analytical thinking, and executive function.




The Cultural Evolution of Epistemic Practices

Oracle BoneThroughout history, people have used information from different sources and have evaluated the relative reliability of various kinds of information based on collectively accepted standards. Much research assumes the universality of epistemic practices, yet history presents plenty of cases where both the epistemic methods and epistemic evaluations exhibit significant variation. For example, an argument that consists of divine revelation, analogy, and words from wise sages would be viewed as convincing in ancient China but weak in most contemporary Western societies. Traditionally, anthropologists have documented indigenous epistemic methods through participant observation, psychologists have measured punitive attitudes towards norm violations, cognitive scientists have modeled belief-updating and decision making processes, and communication researchers have proposed criteria for good persuasive arguments. Yet there is no unified account that takes into consideration the cross-cultural and historical variations in the kind of information that people pay attention to, as well as how information is processed, presented, and evaluated. Kevin Hong, sixth year graduate student, will conduct a set of field studies to examine how individuals in small scale societies in SW China 1) gather information, 2) weigh contradictory information from different sources, and 3) evaluate arguments consisting of different kinds of information normatively. This field study is part of a larger project where he examines the change in rhetorical style in ancient China and the evolution of divination practices. Methodologically, he will combine participant observation, structured/semi-structured interviews, experiments, vignettes, and decision-making modelling. Funded by Mind, Brain and Behavior at Harvard University.


Ostracism and the Evolution of Cooperation in Public Goods Games
ostracismThe ostracism of defectors is often assumed to be viable strategy permitting the evolution of cooperation in public goods games. However, decreasing group size can also cause harm to oneself. To evaluate the viability of ostracism as a strategy, Graham Noblit, sixth year graduate student, will construct an evolutionary game-theoretic model of a group-living organism which earns a positive externality from living in a group of size n and which participates in a public goods game. He will consider two cooperating strategies, one which abandons a group with any defectors and one which ostracizes defectors from groups. The former strategy is particularly interesting because it is not subject to the second-order free-rider problem. Graham will evaluate the evolutionary viability of these strategies in the face of defection, and relate this viability to ecological determinants


The evolutionary role of cultural learning in humans’ ultrasocial cooperation

Cooperation among humans is idiosyncratic in its pervasiveness, diversity of setting, predisposition towards egalitarian outcomes, and occurrence between large numbers of non-kin individuals. Traditional evolutionary models predict that such a degree of cooperation is unlikely to evolve among idealized self-interested agents. Peter S. Park, a fifth-year Ph.D. student in the Harvard mathematics department, is collaborating with Professor Joe Henrich to help explain this puzzle. The proposed evolutionary cause of humans’ ultrasocial cooperation is their unprecedented evolutionary strategy based on intergenerational knowledge accumulation: on cultural learning. This hypothesis will be corroborated by constructing and investigating veridical evolutionary models of ancestral humans that incorporate the key mechanism of cultural learning.



Cross-cultural Study of Cultural Shifts during COVID in Concerns, Activities, and Values


Visiting in the lab from UCLA, Prof. Patricia Greenfield will be working on a cross-cultural study in the United States, Mexico, Indonesia, and Japan of shifts during COVID. In January, 2021, she and her collaborators published a study applying her theory of social change, cultural evolution, and human development to shifts in online behavior that occurred in the United States during the pandemic. They predicted and found shifts towards concerns, activities, and values characterizing the ecology of subsistence villages. Analysis of more than a half-billion data points – words posted in Google searchers and social media (e.g., Twitter) – showed that mortality salience, subsistence activities, and collectivistic values increased significantly during the 70 days following Pres. Trump’s emergency COVID declaration ( Large-scale surveys in the U.S., now in press, confirmed the online shifts in offline behavior. In addition, the surveys showed that people were adapting to increased mortality salience and stay-at-home orders by shifting child rearing and family functioning toward behavior typical of socially isolated subsistence villages with short life expectancies. With a team located in Cambridge, Los Angeles, and Toronto, she will be working on a cross-cultural replication and extension of the online study, adding Twitter data from Mexico, Indonesia, and Japan. A major goal is to show that shifts in mortality salience, subsistence activities, and collectivistic values during the pandemic are responsive to actual COVID mortality rates as they rise and fall from day to day