Social norms are customary or ideal forms of behavior to which individuals in a group try to conform. From an analytical standpoint, the key feature of social norms is that they induce a positive feedback loop between individual and group behavior: the more widely that a norm is practiced by...

This paper offers an analytical narrative based on an assurance game with two separate populations in an evolutionary setting. In our model, Donors and Recipients are two populations; let us call them Europe and Ukraine. The donor population has two types. A proportion of this population wants...

There is continuing debate about what explains cooperation and self-sacrifice in nature and in particular in humans. This paper suggests a new way to think about this famous problem. I argue that, for an evolutionary biologist as well as a quantitative social scientist, the triangle of two...