Green Beard Effect

The Green Beard Effect is a theory in biology where individuals recognize and help others who share a specific trait—like a "green beard." In nature, this means an organism might have a visible trait indicating it carries genes for cooperation or altruism. When they see this trait in others, they preferentially assist or cooperate with them, promoting the survival of those shared genes. Essentially, it's a form of indirect recognition that encourages altruistic behavior among individuals with a common trait, even if they are not closely related genetically.