doi: 10.3389/fpsyg.2013.00812 Language evolution and recursive thought

In simplest terms, language is the syn-tactic combination of concepts (seman-tics), which are mnemonically addressed with man-made sensory-based represen-tations (word-forms). The evolution of language, therefore, is minimally the evo-lution of competency for learning the grammar and words of a given language. Apes have an ability to learn symbol-concept associations across several modal-ities, albeit an impoverished ability. No conclusive demonstration, however, exists for grammatical processing in non-human primates. Grammar, thus, appears to be the more recent and unique innovation