Stephen Le I am a biological anthropologist with research interests in human cooperation, societal trust, temporal discounting (i.e. patience), geographical factors that affect the development of societies, and international development. I am currently conducting postdoctoral research at Hokkaido University, Japan on cooperation, trust, temporal discounting, and crime. My research methods involve evolutionary theory, game theory, behavioral economic experiments, cross-national datasets, structural equation modeling, and field studies. After completing my Masters degree in International Relations at the School of Advanced International Studies, Johns Hopkins University, in Washington, D.C. (2003), I moved to the University of California, Los Angeles, and received a Ph.D. in biological anthropology (2010). My initial research program at UCLA focused on a theoretical model of cooperation, the continuous prisoner’s dilemma.  The prisoner’s dilemma is a model that is commonly used in the social sciences (for example, economics, political science, psychology, and anthropology) and biological sciences to try to analyze interactions between humans or animals.  The prisoner’s dilemma presents a simplifed scenario in which two interacting agents can benefit from cooperating together, but each individual also stands to gain from ‘cheating’ on the other partner.  Using this model, researchers hypothesized that a simple ‘tit-for-tat’ strategy would be quite robust in most situations, especially if the partners interacted over long time horizons.  However, one weakness of this model is that it applies to situations in which there are two choices, cooperate or defect.  My research focused on making this model more realistic, by studying situations in which partners may contribute any amount along a spectrum of cooperation – this is referred to as a continuous iterated prisoner’s dilemma (CIPD), as opposed to a discrete iterated prisoner’s dilemma (DIPD).  According to the DIPD, cooperation should be quite common in nature; however, it turns out that cooperation is quite rare in nature.  The CIPD model that I developed with Rob Boyd suggests why this is the case – essentially, it is much harder to evolve cooperation in a CIPD because the baseline condition of non-cooperation is quite robust. After working on the CIPD, my research turned to empirical studies of human cooperation and time discounting.  Time discounting is a phenomenon whereby people are observed to prefer sooner rather than later rewards, everything else being equal.  It has been noted that children who have the tendency to defer gratification early in life tend to earn better academic achievement in the long run.  Several studies conducted in the USA have found that undergraduate students who are more patient in time discounting tasks also tend to be more cooperative in experimental economic games.  However, two studies of time discounting and cooperation conducted outside the USA found no such result.  I wanted to know if this phenomenon were true in non-Western countries, and if so, why.  I conducted experiments on time discounting and cooperation at UCLA in May of 2007, in northern-central Vietnam in April 2008, and in southern Vietnam in June 2008.  Interestingly, the experiments at UCLA and in northern Vietnam followed the previously-obtained pattern of correlation between patience and cooperation, but in southern Vietnam, the pattern was opposite.  I believe that this can be explained by historical differences between northern-central and southern Vietnam.  In southern Vietnam, people are accustomed to a capitalistic way of life; this means that students who participated in these experiments were focused on money-maximization.  For such people, being patient implies being uncooperative, because in both cases, one may maximize one’s return.  By contrast, in northern-central Vietnam, and presumably the USA, people focus on dely or uncertainty, and thus being patient implies being cooperative.  For these people, cooperation in economic games means that one has to wait for a higher return, whereas cheating automatically guarantees the highest return. Publications: - (with Robert Boyd) Evolutionary dynamics of the continuous iterated Prisoner’s dilemma. Journal of Theoretical Biology 245 (2007) 258–267. - Are Patient People More Cooperative? Contrasting Results from Northern and Southern Vietnam (submitted) - Geographical Latitude and Societal Outcomes (submitted) In my free time, I enjoy playing the piano, playing basketball, dancing Argentine tango, and exploring the outdoors.