société (humaine) (1) association (1) aliment (1) expérience scientifique (1) Money (1) Food (1) Tokens (1) Social groups (1) Performance (1) Money (1) Human beings (1) Food (1) Finance (1) Exchange (1) Chains (1) Capuchin monkeys (1) Back (1) Animals (1) Ability (1) Finance (1) Validity (1) Use (1) Number (1) Performance (1)