>...their language development was in all three cases way ahead of schedule. I would put a lot more of it to having (seemingly) engaged parents. Even a backwar

>...their language development was in all three cases way ahead of schedule. I would put a lot more of it to having (seemingly) engaged parents. Even a backwards strategy enacted by a loving parent who is consistently trying their best is likely to outperform the result that most can manage (owing to time/money/education/etc).