>>10579215Occum's Razor.
I can't find the study, but linguistically, there is a relationship between grammar, vocabulary, accent, the size of the population using the language, and density of the geography of the population.
So English has simple grammar and complex vocabulary with a wide variety of pronunciations because of the way it developed and that the British spread English around the world. As you move down the manifold, the smaller the population, the more dense, the fewer people who speak the language, the less variance in pronunciation, the fewer words, BUT the more complex grammar.
As for the story of brain development, you are putting the cart before the horse in a world without horses. You have an a priori conclusion that a brain that can handle more words defines the condition of a complex brain. But if it is only defined as complex because of the complex language, than any differentiation will be attributed to that and will define complex.
Yet if you a priori defined a complex brain as one that can live in, let's say a hunter gatherer society, then those differences in the brain of teh hunter gather from the linguistically defined brain would now then be considered more advanced.
That's why in real science we use control groups of statistically independent sources corrected for population density.
