Genetics and Language

by

Dan Dediu, Sarah Graham

• LAST REVIEWED: 30 August 2022
• LAST MODIFIED: 27 March 2014
• DOI: 10.1093/obo/9780199772810-0184

Introduction

This article surveys what is currently known about the complex interplay between genetics and the language sciences. It focuses not only on the genetic architecture of language and speech, but also on their interactions on the cultural and evolutionary timescales. Given the complexity of these issues and their current state of flux and high dynamism, this article surveys the main findings and topics of interest while also briefly introducing the main relevant methods, thus allowing the interested reader to fully appreciate and understand them in their proper context. Of course, not all the relevant publications and resources are mentioned, but this article aims to select the most relevant, promising, or accessible for nonspecialists. The main author of this article, Dan Dediu, was funded by the NWO (Netherlands Organisation for Scientific Research) Vidi Grant no. 276-70-022. The authors also want to thank the members of the Language and Genetics Department, Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands, for helpful suggestions.

The Genetic Architecture of Language

The view that genetics must contribute to our species’ linguistic abilities has existed for many years, as illustrated by Chomsky 1959 and Lenneberg 1967, with Pinker and Bloom 1990 offering an influential evolutionary point of view. However, the discovery of concrete genetic influences on language had to await the development of modern DNA technologies. As has been the case for many aspects of human biology, the first insights into the genetic basis of language have come from the study of disorders, discussed in detail in the sections Rare Speech and Language Disorders and Common Disorders of Speech and Language. The classification of disorders as rare or common very likely reflects the underlying architecture—rare diseases tend to be caused by single mutations of large effect within one particular gene, while common ones have more heterogeneous genetic architectures involving common variants with small effect, as well as rare variants in a number of different genes. While rare disorders can clearly be classified as abnormal, the genetic architecture of common disorders puts them on a spectrum with normal variation. Discussions of the genetic architectures of complex traits and common neurodevelopmental disorders, a useful context in which to understand language and speech, are provided in Betancur 2011 and Durand and Rappold 2013.

• Betancur, C. 2011. Etiological heterogeneity in autism spectrum disorders: More than 100 genetic and genomic disorders and still counting. Brain Research 1380:42–77.

  DOI: 10.1016/j.brainres.2010.11.078

  Discussion of genetic findings relating to autism, a common neurodevelopmental disorder that includes communication difficulties and has a highly heterogeneous genetic underpinning.

• Chomsky, Noam. 1959. A review of B. F. Skinner’s verbal behavior. Language 1:26–58.

  DOI: 10.2307/411334

  This well-known paper, which generated a revolution in cognitive science, argues for a biological basis for language.

• Durand, C., and G. A. Rappold. 2013. Height matters: From monogenic disorders to normal variation. Nature Reviews. Endocrinology 9.3: 171–177.

  DOI: 10.1038/nrendo.2012.251

  This review takes height as an example of a heritable trait influenced by both common and rare genetic variants. Given that height has several highly desirable properties in a phenotype and its genetic basis is relatively well understood, the article provides a very useful background against which to understand the issues faced when one is studying the genetics of language and speech.

• Lenneberg, Eric H. 1967. Biological foundations of language. New York: Wiley.

  A very important early book arguing for a biological basis for language, reviewing several strands of evidence such as the proposed existence of a critical period for language acquisition and language pathologies.

• Pinker, S., and P. Bloom. 1990. Natural language and natural selection. Behavioral and Brain Sciences 13:707–784.

  DOI: 10.1017/S0140525X00081061

  A seminal argument that language is a product of natural selection, this article assumes that there is a genetic basis for language. Some of these assumptions, however, might seem rather simple, given what we currently know about the genetic foundations of language and speech.