There is a mismatch between the conceptual capacities of animals and the communicative content of their vocal and visual signals. For example, although a wide variety of nonhuman primates have access to rich knowledge of who is related to whom, as well as who is dominant and who is subordinate, their vocalizations only coarsely express such complexities.#Quoted in Chris Knight, “Puzzles and mysteries in the origins of language” (2016)