Editing Sign language (section)

=== Gestural theory of human language origins ===
{{Main|Origin of language#Gestural theory|l1=Origin of language § Gestural theory}}

One theory of the evolution of human language states that it developed first as a gestural system, which later shifted to speech.<ref>{{Cite journal | doi = 10.1086/201401 | last1 = Hewes | first1 = Gordon W. | year = 1973 | title = Primate communication and the gestural origin of language | journal = Current Anthropology | volume = 14 | pages = 5–32 | s2cid = 146288708 }}</ref><ref>Harnad, S. R., Steklis, H. D., & Lancaster, J. E. (1976). Origins and evolution of language and speech. ''Annals of the New York Academy of Sciences'' 280.</ref><ref>Kimura, Doreen (1993). ''Neuromotor Mechanisms in Human Communication''. Oxford: Oxford University Press.</ref><ref>Wittmann, H. (1980). Intonation in Glottogenesis. ''The Melody of Language'' 315.</ref><ref name="Wittmann, H. 1991"/><ref>
{{Cite journal | doi = 10.1038/nn775 | last1 = Newman | first1 = A. J. | last2 = Bavelier | year = 2002 | first2 = D | last3 = Corina | first3 = D | last4 = Jezzard | first4 = P | last5 = Neville | first5 = HJ | title = A Critical Period for Right Hemisphere Recruitment in American Sign Language Processing | journal = Nature Neuroscience | volume = 5 | issue = 1| pages = 76–80 | pmid = 11753419 | s2cid = 2745545 }}</ref>  An important question for this gestural theory is what caused the shift to vocalization.<ref>Steklis, H. D., & Harnad, S. (1976). From hand to mouth: Some critical stages in the evolution of language. In Origins and evolution of language and speech (pp. 445-455). ''Annals of the New York Academy of Sciences'' 280.</ref><ref>Kolb, Bryan, and Ian Q. Whishaw (2003). ''Fundamentals of Human Neuropsychology'', 5th edition, Worth Publishers.</ref><ref>Blondin-Massé, Alexandre; Harnad, Stevan; Picard, Olivier; and St-Louis, Bernard (2013) [https://eprints.soton.ac.uk/271438/1/Harnad-Lefebvre-bookFIN-REV.pdf Symbol Grounding and the Origin of Language: From Show to Tell] {{Webarchive|url=https://web.archive.org/web/20220121152032/https://eprints.soton.ac.uk/271438/1/Harnad-Lefebvre-bookFIN-REV.pdf |date=2022-01-21 }}. In, Lefebvre, Claire; Cohen, Henri; and Comrie, Bernard (eds.) ''New Perspectives on the Origins of Language.'' Benjamin</ref>