Fish can determine their social rank by observation alone, study finds
...requires combat among males will have some kind of eavesdropping capability allowing them to surreptitiously draw inferences about their social rank," Fernald said. "Cognitive capacities that evolved in fish may contribute to human transitive inference, or perhaps this capacity evolved independently. The question ...Long before the National Security Agency began eavesdropping on the phone calls of Americans, young song sparro...nce that young birds choose many of their songs by eavesdropping on the tuneful interactions between other sparrows. In laboratory experiments, the young sparrows...