When faced with danger, seek refuge in the herd: A study on the stability of cooperation strategies under evolving incentives.

Abstract: Understanding the mechanisms that drive human non-kinship cooperation is an important aim of behavioural economic literature. However, many results are based on observations in abstract games under context-specific conditions which limits the external validity of conclusions. With time, these abstract games have become more complex and have relaxed their restrictive assumptions, but are still far from modelling the intricacies of human decision making in society. One such limitation of cooperation experiments that has received little attention is the assumption that individuals formulate constant strategies that may or may not be conditional on the social norm. This thesis studies the dynamics of cooperative phenotypes under varying levels of high external threat using a series of fixed effects linear probability models applied to data sourced from the US TV series: Survivor. I find that as the external threat increases, individuals display a decreasing propensity to cooperate and a decreasing sensitivity to the social norm for cooperation. A non-linear analysis reveals the interdependent relationship between social norms and private payoff incentives. Hence, I propose that to maintain cooperation in high-threat settings, it must be that either there is a strong social norm for cooperation that includes credible social punishments, or that the threat is framed as surmountable, which may then endogenously create such a social norm.