I’m not sure that really addresses the issue. I didn’t quote the passage that explicitly mentions it but the “enormous amount of time and effort” is important because it’s an enormous opportunity cost. The article you linked says, among other things, that
[Children] can devote almost their full time to [learning their language]. Adults consider half an hour’s study a day to be onerous.
I don’t doubt that children spend a tremendous fraction of their time learning their language, just as they spend a tremendous fraction of their time maturing in other ways. But that doesn’t necessarily translate to a significant opportunity cost, because children are doing other things throughout their day as they learn their language. One way to measure the opportunity cost associated with each additional language learned might be to see how much and in what ways bilingual and trilingual children lose out in exchange for learning languages two and three. The linked article mentions that children won’t learn a second language if they can get along with just one, which tells us that there is some cost associated with learning each additional language, but that doesn’t really tell us how great the cost is.
Note also that while kids will pick up languages faster, more spontaneously, and with better results (the ability to pick up a flawless accent and perfect command of finer points of grammar usually disappears in late childhood), they will also forget them unbelievably quickly and thoroughly without active use. As an adult, your command of a language may get rusty, but it will never fall to zero as long as your brain is functioning decently. On the other hand, kids who change environments may forget even their first native language so thoroughly that they’ll be barely able to recall a single word.
Unless the learner is a child—or so I’ve heard.
This may not actually be true.
I’m not sure that really addresses the issue. I didn’t quote the passage that explicitly mentions it but the “enormous amount of time and effort” is important because it’s an enormous opportunity cost. The article you linked says, among other things, that
I don’t doubt that children spend a tremendous fraction of their time learning their language, just as they spend a tremendous fraction of their time maturing in other ways. But that doesn’t necessarily translate to a significant opportunity cost, because children are doing other things throughout their day as they learn their language. One way to measure the opportunity cost associated with each additional language learned might be to see how much and in what ways bilingual and trilingual children lose out in exchange for learning languages two and three. The linked article mentions that children won’t learn a second language if they can get along with just one, which tells us that there is some cost associated with learning each additional language, but that doesn’t really tell us how great the cost is.
Note the “adult” qualification in the first sentence of my comment.
Ah, I missed that!
Note also that while kids will pick up languages faster, more spontaneously, and with better results (the ability to pick up a flawless accent and perfect command of finer points of grammar usually disappears in late childhood), they will also forget them unbelievably quickly and thoroughly without active use. As an adult, your command of a language may get rusty, but it will never fall to zero as long as your brain is functioning decently. On the other hand, kids who change environments may forget even their first native language so thoroughly that they’ll be barely able to recall a single word.