The dominance hierarchy of chickens and other birds that he studied led him to the observation that these birds had established the order in which individuals would be allowed to get to food while others would have to wait for their turn.
Den dominans hierarki hos kycklingar och andra fåglar som han studerade ledde honom till observationen att dessa fåglar hade etablerat en ordning i vilken enskilda skulle tillåtas att komma till livsmedel, medan andra skulle behöva vänta på sin tur.