Genes and the conceptualisation of language knowledge

While it would be difficult to dispute that individuals vary in their facility with both their native language and with foreign languages, a central tenet of modern linguistics has been that such variation is secondary, and there is a primary level of equality across all individuals. Syntactic theory and sociolinguistic theory have both contributed to the maintenance of this view, and it provides a socially acceptable approach to studying language form and function. However, genes are the authors of both similarity and difference, making their role in language complicated to unpick. The proposed syntactic basis for equality has been a genetically-determined 'language faculty', which presumably arose early in the modern species and has reliably persisted in all individuals until today. How much fundamental uniformity of language knowledge is there, though? Does it matter if a key feature is not observed in unwritten languages, if there are languages that permit structures that should be prohibited, or if some individuals are less adept at managing purportedly universally understood configurations than others? How might culturally augmented features in language structure be inappropriately influencing claims about what all languages are like? These questions are directly relevant to those engaging with genetics because of the growing opportunities to explore the relative roles of environment and genes in determining aspects of our language knowledge and performance. More generally for society, they present an uncomfortable challenge for how we should handle evidence of genetically-based differences in fundamental language ability, should we find it.