Social evolution and the two elements of causation

The kin selection theory has recently been criticised on the basis of claiming that genetic relatedness does not play a causal role in the social evolution among individuals of insect societies. We outline here a line of criticism of this view by demonstrating two things. First, there are strong conceptual, theoretical and empirical reasons to think that close genetic relatedness has been necessary for the rise of the helper castes of social insects. And second, once we understand how causal explanation itself results from an interplay of two logically distinct elements, necessity and sufficiency, we can also understand the scenarios in which relatedness does not seem to play a causal role for evolution of helper castes. The result of this analysis is that we should be more careful about the way we frame the empirical data on the evolution of social behaviour.