Tag-based spite with correlated interactions.

We use evolutionary game theory to study the evolution of harming behavior (spite) in settings involving both tags and (anti-) correlated interaction. Our results show an interesting interaction between these mechanisms. The presence of tags shows that pure spite is less likely to evolve when theoretically expected, but that conditional spite is more likely than expected. Moreover, we identify a novel tag-based equilibrium where spite occurs within but not between groups. We discuss implications for the evolution of spite, punishment, and the methodological approach of using exogenous parameters to represent (anti-) correlated interactions.