And in terms of learning multiple languages during development, my understanding is that if one wants to become bilingual or trilingual, best to learn those languages simultaneously during development, ideally before age 12, if one hopes to not have an accent in speaking them later. Is that correct? The earlier is better.

The more intense it is and the more immersive it is, the longer you know that you can be exposed to that is really important. A lot of people can get exposed to early and basically lose it even though it's quote unquote during that sensitive period. Unless it's maintained, it can be very easily lost.

Then I think another aspect of it that's very interesting is some of the social requirements for it too. It's pretty clear that you can only go so far just listening to these sounds from a tape recording or something like that. There's something extra about real human interactions that activates the brain sensitivity to different speech bounds, allows us to become specialized for them for a given