Innateness and culture in the evolution of language
- *School of Philosophy, Psychology, and Language Sciences, University of Edinburgh, 40 George Square, Edinburgh EH8 9LL, United Kingdom;
- ‡Department of General Systems Sciences, Graduate School of Arts and Sciences, University of Tokyo, 3-8-1 Komaba, Tokyo 153-8902, Japan; and
- §Department of Psychology and Program in Cognitive Science, University of California, Berkeley, CA 94720
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Edited by Richard M. Shiffrin, Indiana University, Bloomington, IN, and approved February 6, 2007 (received for review September 19, 2006)
Abstract
Human language arises from biological evolution, individual learning, and cultural transmission, but the interaction of these three processes has not been widely studied. We set out a formal framework for analyzing cultural transmission, which allows us to investigate how innate learning biases are related to universal properties of language. We show that cultural transmission can magnify weak biases into strong linguistic universals, undermining one of the arguments for strong innate constraints on language learning. As a consequence, the strength of innate biases can be shielded from natural selection, allowing these genes to drift. Furthermore, even when there is no natural selection, cultural transmission can produce apparent adaptations. Cultural transmission thus provides an alternative to traditional nativist and adaptationist explanations for the properties of human languages.
Footnotes
- †To whom correspondence should be addressed. E-mail: simon{at}ling.ed.ac.uk
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Author contributions: S.K., M.D., and T.L.G. designed research; S.K., M.D., and T.L.G. performed research; and S.K., M.D., and T.L.G. wrote the paper.
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The authors declare no conflict of interest.
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This article is a PNAS direct submission.
- © 2007 by The National Academy of Sciences of the USA
