Social and socio-
Ontogeny and symbolism
Primate communication, lies, and ideas
Communications which are interestingly symbolic involve a partial detachment from the referent: one criterion of a proto-linguistic mentality is how good it is at lying. Primate taxonomy does not correspond one-to-one with social structures. It correlates more closely with complexity of social intelligence. Our near relatives, the chimpanzees and bonobos, have male-bonded societies in which females migrate between troops, and individuals leave and rejoin the group. This means an individual potentially has private information it could share or withhold. Vocalizations of monkeys, and probably apes, contain semantic detail about social relations as well as external threats. Chimpanzees give food-calls in the wild which attract others; in captivity they can lead others to hidden food, and convey its quality. Apes, and occasionally monkeys, deliberately deceive others, concealing both food and sex, and even facial expressions or erections. Apes (but not monkeys) recognize themselves, removing marks from their faces in mirrors, and can take others' roles in shared experiments. The capacities to give or withhold information and to be aware of others' intentions may be pre-requisites for the capacity to manipulate signs detached from the immediate: in other words, to have an idea.