Some aspects of language and speech might be under the influence of genetic biases. Such biases, while weak at the individual level,  are nevertheless able to affect language change through the repeated cultural transmission of language across generations of genetically biased speakers.This process could help explain some patterns of linguistic diversity (when populations differ in their genetic makeup), while also generating universal tendencies (when the biases are shared across the entire species).

This five-years project, funded by a Netherlands Organization for Scientific Research (NWO) Vidi Grant, will focus on the investigation of such genetic biases in the area of speech production, looking at the effects of variation in the speech organs on language and speech. The project is highly interdisciplinary with a strong quantitative approach and will explore multiple avenues. We will conduct extensive literature reviews encompassing several fields (such as physical anthropology, dentistry, phonetics, speech pathology, medical genetics and forensic science), we will collect the much needed primary data on variation in the speech organs using cutting-edge technologies and use computer models of the vocal tract to understand their effects on speech, and we will employ and develop new quantitative methods inspired from evolutionary biology to analyze such biasing processes.

The project is hosted within the Language and Genetics Department and involves close collaborations with the Language and Cognition Department.

Relevant publications:

• Levinson, S. C., & Dediu, D. (in press). The interplay of genetic and cultural factors in ongoing language evolution. In Strungmann Forum Reports: Cultural Evolution. Cambridge, Mass: MIT Press.
• Gialluisi, A., Dediu, D., Francks, C., & Fisher, S. E. (2013). Persistence and transmission of recessive deafness and sign language: New insights from village sign languages [Letter]. European journal of human genetics. doi:10.1038/ejhg.2012.292.
• Dediu, D. (2011). A Bayesian phylogenetic approach to estimating the stability of linguistic features and the genetic biasing of tone. Proceedings of the Royal Society of London/B, 278: 474-479. doi:10.1098/rspb.2010.1595.
• Dediu, D. (2011). Are languages really independent from genes? If not, what would a genetic bias affecting language diversity look like? Human Biology, 83: 279-296. doi:10.3378/027.083.0208.
• Dediu, D., & Ladd, D. R. (2007). Linguistic tone is related to the population frequency of the adaptive haplogroups of two brain size genes, ASPM and Microcephalin. PNAS, 104: 10944-10949. doi:10.1073/pnas.0610848104.

Staff:
Dan Dediu

Collaborators:
Stephen C. Levinson (MPI Nijmegen, Language and Cognition)
Michael Dunn (MPI Nijmegen, Evolutionary Processes in Language and Culture)
D. Robert Ladd (Edinburgh University, UK)
Bart de Boer (Vrije Universiteit Brussel, Belgium)
Heriberto Avelino (MPI Leipzig, Deptartment of Linguistics)
Didier Demolin (Université Stendhal, France)