Good question :) not sure I have a good answer for that one, although I'd like to point out that many people elect to expend mental energy on otherwise unproduc

Good question :) not sure I have a good answer for that one, although I'd like to point out that many people elect to expend mental energy on otherwise unproductive minutia (aka. hobbies) so perhaps the task of carrying on a spoken tradition is less onerous to some than one might expect. Language contributing to group segregation is a very strong claim, however, and if you have any case studies (or, like, newspaper articles, this isn't academia) I'd be interested in seeing them.