CONCEPT
Kin Selection
W.D. Hamilton's 1964 mathematical solution to the puzzle of altruism — the consilient insight that extended evolutionary theory into social behavior and founded sociobiology.
Before Hamilton, altruistic behavior — an organism reducing its own reproductive success to benefit another — appeared to contradict natural selection. If selfish individuals outreproduce altruistic ones, altruism should disappear. Hamilton's 1964 papers on 'The Genetical Evolution of Social Behaviour' solved the puzzle with a simple mathematical framework: altruism is evolutionarily stable when the benefit to the recipient, weighted by the recipient's genetic relatedness to the actor, exceeds the cost to the actor. In formula: rB > C. Siblings share half their genes; aiding a sibling at modest cost to oneself can be genetically advantageous even though the individual-level arithmetic appears to make no sense. Wilson recognized Hamilton's work as the foundational consilient insight that would allow evolutionary theory to be extended into social behavior across the animal kingdom — including, eventually and controversially, into human beings.
In The You On AI Field Guide
Hamilton's framework explains a vast range of biological phenomena that had puzzled earlier naturalists: the sterile worker castes in social insects, parental care, sibling rivalry, the organization