Common origin of linguistic and movement abilities.
We start with the view that the development of systems of symbols is rooted in the regulation of cellular processes and the behavior of unicellular animals. Animals would thereafter start to externalize these internal symbol systems, to coordinate movements with each other. We propose that the brains of multicellular animals can be understood as a continuing elaboration of the early chemical symbol systems of unicellular animals: the labile symbols of the unicellular animal are replaced by hormones, more stable chemical compounds, and nerves that are seen as more stable and more specific routes of activation; and brains developed layers of symbols such that the domain of a symbol is not a set of bodily processes but rather a set of brain processes. Human language is very much in the "style" of the rule-governed symbol manipulation required by all behaving animals, although unique in its complexity. We suggest that the essential question is not how humans have evolved symbolic and linguistic abilities from a primitive sensorimotor brain but rather how do symbols come to exist in biological systems and what is useful and necessary about a system of symbols for the coordination of action within animals and among animals.
D000818:Animals; D001921:Brain / Q000502:physiology*; D000242:Cyclic AMP / Q000378:metabolism; D004023:Dictyostelium / Q000502:physiology; D004926:Escherichia coli / Q000502:physiology; D006801:Humans; D007802:Language; D008037:Linguistics; D008960:Models, Psychological; D009043:Motor Activity; D009068:Movement; D013045:Species Specificity
D000242:Cyclic AMP