A hierarchy within a social group or community, in which those members at the top assume positions of leadership, authority, and power. The expression originated from a description of social behavior among chickens, which attack each other by pecking to establish dominance.
The hierarchy of authority in a group, as in On a space mission, the astronauts have a definite pecking order. This expression, invented in the 1920s by biologists who discovered that domestic poultry maintain such a hierarchy with one bird pecking another of lower status, was transferred to human behavior in the 1950s.
