What price kindness?(The Price of Altruism: George Price and the Search for the Origins of Kindness)

Where science had offered either the narrowness of nepotism (kin selection) or the clannishness of the tribe (group selection) as possible explanations for the evolution of altruism, the "Price equation" would provide a multilevel selection approach that would allow for both, and more. By partitioning selection into its different components- particularly for traits like altruism where interests apparently conflict between different levels of biological organization- the equation would ultimately find a central role in social evolution theory.