Comment by nkrisc

> Isn't this in contradiction to the observations of severely neglected or feral children who having never learned language as a child cannot learn it later in life?

No. Language learning ability does change as the brain matures, but all humans (barring some pathology) possess the ability as infants to learn any human language. They're essentially learning a second vocal language without having ever learned their first. And of course, not all languages are even spoken, such as sign language.

Sure, lots of animals have evolved vocal communication, possible even all from a common ancestor, but none are comparable to human language. There is no limit inherent limit to the information human language can express.

My understanding of the current state of linguistics and evolutionary biology is that communication-first theories are not generally considered likely, though of course it is not settled and likely won't be for a long time (if ever).