Evolution
Kin Selection
Natural selection that favors behaviors benefiting genetic relatives, even at cost to the individual. Explains altruistic behavior toward relatives based on shared genes.
Biological Context
Hamilton's rule states that altruism evolves when the benefit to relatives, weighted by relatedness, exceeds the cost to the altruist. This explains sterile worker castes in social insects (sisters share 75% of genes), alarm calls in ground squirrels, and parental care. Inclusive fitness includes both direct reproduction and helping relatives reproduce.
Business Application
Organizational kin selection: people favor those they perceive as similar (same team, department, background). Understanding this helps explain in-group bias and the importance of shared identity.