In Graphs, Maps, Trees, Franco Moretti writes the following:
Divergence prepares the ground for convergence, which unleashes further divergence: this seems to be the typical pattern. Moreover, the force of the two mechanisms varies widely from field to field, ranging from the pole of technology, where convergence is particularly strong, to the opposite extreme of language, where divergence is clearly the dominant factor; while the specific position of literature—this technology-of-language—within the whole spectrum remains to be determined (80).
I’m taking this quote out of its context, but I want to zero in on Moretti’s assumption that the rule of linguistic evolution is divergence rather than convergence.
The assumption is true in many respects, but it’s not the whole picture. It’s the whole picture only if we idealize the data . . . and idealize it beyond acceptable measures, in my opinion.
(Note: I can’t say enough good things about Moretti; read his stuff if you haven’t already. I’m just using him as a foil here.)
I’ve written elsewhere on how English itself is a converged language . . . it was birthed in the convergence of Old French and Old English. But the same linguistic convergence occurs at different levels all the time. We call it ‘borrowing’, ‘creoles’, ‘pidgins’, et cetera. As if giving these occurrences a special name obviated the need to deal with them in our linguistic phylogenies and our theories of language change.
Even if most whole languages aren’t always the result of convergence, there is nevertheless convergence on smaller scales. Phonology, morphology, syntax, the lexicon . . . there are many levels at which convergence can occur.
I think there’s much insight to be had from comparing human populations and human languages. Human races do not have distinct boundaries (they seem to form fuzzy clusters); that doesn’t mean they don’t exist, just that they don’t have distinct boundaries. Likewise, ‘languages’ obviously exist, they just don’t have distinct boundaries. In human populations, genotypes and phenotypes separate the clusters to a certain extent; in linguistics, we have phonology, morphology, and syntax.
Fuzzy boundaries . . . i.e., certain dialects (populations) of a language will have received some input from some other linguistic population at the phonological, morphological, syntactic, or lexical level.
faxear . . . an English lexeme (fax) has been absorbed at the level of Spanish verb morphology.
Along the Mexican border, if you show a gringo a made up word that has two adjacent l’s in it (e.g., kohilla), they’re going to pronounce those l’s with Spanish phonology [j].
German has changed at the lexical, syntactic, and idiomatic level thanks to the popularity of English. Try finding heiße used to mean “popular” before 1970. (Or Booty shaken kann, for that matter.)
Languages can be seen as networks of influence at different scales, with more or fewer edges depending on the kind of contact two linguistic populations have had. Not always, of course, but more often than most people think. And there are obvious diachronic implications. Does this mean we should throw out the notion of standard languages? Of course not. It just means that even the purest standard will likely have some admixed influence from another language at some level or in some lexical entry.