> Language complexity is a hotly debated topic in linguistics, with many different opposing views.

They bring this up, don’t address it, then proceed to the results anyways.

The idea of grammatical or language complexity is very dubious. They seem to define it by number of distinctions. But, how is that inherently more complex?

Wouldn’t we expect Russian children to start speaking later than, say, Chinese children? But we don’t actually see that, all children seem to learn their respective mother tongues at about the same rate.

Now, if you’re an adult monolingual English speaker trying to learn Russian, then I’m sure the crazy conjugation and declination systems would appear complex. But it’s probably simply different rather than complex.

5 year old Russians seem to think that case declinations are the easiest thing in the world!