Much of the discussion here is focused on the linguistic acquisition aspects of this article. I see the largely ignored wider aspect to be that of skills learning, particularly in light of
unlearning and lost plasticity.
The key paragraphs are these:
"[A] 2-year-old’s brain has a substantial neurological advantage, with 50 percent more synapses — the connections between neurons — than an adult brain, way more than it needs. This excess, which is an insurance policy against early trauma, is also crucial to childhood language acquisition, as is the plasticity, or adaptability, of the young brain.
[NB: I challenge the assumption that the excess neural capacity is simply for trauma recovery -- it seems specifically applicable to the very mental plasticity that youthful skill acquisition entails, and which needs to be discarded as concrete skills are laid down.]
"Another advantage a toddler holds is his very lack of experience. After speaking our native language for decades, we adults can’t help but hear the second language through the filter of the first. And this filter doesn’t take decades to develop. Researchers have found that newborn Japanese babies can distinguish between the English “L” and “R” sounds, but if not exposed to Western languages, they begin to lose that ability — not by the age of 6 or even 3 — but by eight months.
"Adult language learners are, to borrow a phrase used by some psycholinguists, too smart for our own good. We process too much data at once, try to get everything right from the get-go and are self-conscious about our efforts. But toddlers instinctively grasp what’s important and are quite content to say, “Tommy hitted me,” as long as Tommy gets what’s coming to him."
That is, if you're trying to learn something, anything, as an adult, you're up against two principle blocks:
• Your brain has physiologically adapted. It's no longer sufficiently plastic to accept novel concepts.
• You've got a litany of previously acquired skills (or biases) which get in the way of the new knowledge. It's a form of Mark Twain's famous "It's not the things you don't know, but what you know for sure that just ain't so".
Or, in this case, just ain't what the new skill you're trying to pick up is.
Which may also help explain youthful hiring bias in software and tech.