Group selection requires group stability and reproductive isolation across generations: examples of group selection in humans may be hard to find.

The territoriality of male red grouse, whereby some individuals are sacrificed to maintain overall stability, is a testable model of the distribution of inhibition in human family life.

Christmas is an epideictic display in humans.

What explains the persistence of the controversy between kin selection and group selection? Kin selection is easier to model mathematically than group selection: “…our very simple model is too complicated to allow an exact calculation of the fixation probabilities.” The need for a parsimonious explanation fails to distinguish between rules for explanations and explanations, and says more about the cellular strata of the human cerebral cortex than it does about the social strata of the red grouse.