Erez Yoeli - Categorical Norms

Why are norms unduly sensitive to categorical distinctions compared to continuous variation? For instance, the norm against the use of chemical weapons considers the type of weapon used, not how much suffering was caused; human rights are conditioned on membership in the species homo sapiens not on an animal’s degree of sentience; norms promoting philanthropy emphasize donating, and are relatively insensitive to the impact a donation will have. Here we present a game theoretic model, which explains why it is easier for norms to be conditioned on categorical distinctions rather than on continuous variation. We explore the robustness of our results and present evolutionary simulations. Then, in a series of experiments, we demonstrate that participants’ moral intuitions and willingness to sanction norm violations are influenced by categorical distinctions rather than by continuous variation. We also show that the reliance on categorical distinctions weakens when norm enforcement plays less of a role. We discuss various applications, including territoriality, human rights, inefficient altruism, institutionalized racism, and collusion.

Joint work with Moshe Hoffman, Aygun Dalkiran, Bethany Burum, and Martin Nowak.