It seems to go against evolutionary theory for an individual to give up its own chances at reproducing in order to increase the fitness of others. Yet social behavior is found throughout nature, from bacteria and social insects to wolves, whales, and of course humans. What makes self-sacrifice to any degree even possible, given that self-interested behavior is the default? In The Philosophy of Social Evolution
(Oxford University Press, 2017), Jonathan Birch
critically examines the conceptual foundations of social evolution theory, considering debates about kin vs. group selection, cultural as well as genetic transmissible bases of inheritance, and inclusive vs. neighbor-modulated fitness. Birch, an associate professor at the London School of Economics, also discusses the view of multicellular organisms as societies of cells, and extends the concept of genetic relatedness to cultural relatedness by means of common cultural traits.