I think there’s high variation in adults’ ability, low in children’s ability.
A million or more Jews came to Israel from the USSR in 1990-2 (my family among them). Virtually none of them knew any Hebrew (studying or teaching it had been illegal in the USSR), or any other language spoken in Israel (English, Arabic). The immigrants had to learn Hebrew to be able to get jobs, attend school/university/retraining, and interact with local authorities. Local Russian-speaking communities did not yet exist on the requisite scale to take in more than a few newcomers. There was enormous pressure, and all the motivation you could want.
My family was among these immigrants (I was 6 years old at the time), and I’ve met hundreds or thousands of others. There is a very strong negative correlation of age and fluency in Hebrew, even today, after 18 years of immersion. People who immigrated at age 10-15 or younger are fluent speakers, have little to no accent, and it is very remarkable to meet an exception. Among people who immigrated as adults, most are fluent but make grammatical, pronunciation or spelling mistakes, or have vocabulary problems. Among people who immigrated at age ~~ 50-60 or older, many (I estimate at least 20-30%) never progressed beyond rudimentary skills necessary for e.g. shopping, cannot read or write fluently.
There is of course strong correlation between environment post immigration (school, work, non-Russian-speaking workplaces) and ability, but I’ve met enough such people to know that the causation goes both ways.
I suggest that causation operates via the very real change impact on motivation and the willingness to change one’s identity. 18 years of dedicated practice is enough time for nearly anyone to become an expert in nearly anything to a far greater degree than mere competence.
Studies find that adults actually learn languages faster than children do and older children faster than younger. Here is a more subtle investigation of how the motivation of adults interacts with circumstance and language in natural circumstances.
There’s motivation and then there’s motivation. Children are too young to respond to the requirement incorrectly enough to completely fail at it. If your System-2 must learn a new language, but you can still System-1 speak your native tongue within family or with friends, it is a different situation from where a child has no way of communicating at all, and communication is not just an instrumental requirement, it is a powerful instinct. Of course, some older adults will have damaged learning ability and won’t be able to learn a new language, but it’s an entirely different issue.
You’re saying all adults could learn a new language and become fluent if the motivation was on the level of “not being able to communicate with anyone at all”. Is there hard evidence of this? In particular, once such people achieve basic communication, do they reliably move on to fluency?
I think there’s high variation in adults’ ability, low in children’s ability.
A million or more Jews came to Israel from the USSR in 1990-2 (my family among them). Virtually none of them knew any Hebrew (studying or teaching it had been illegal in the USSR), or any other language spoken in Israel (English, Arabic). The immigrants had to learn Hebrew to be able to get jobs, attend school/university/retraining, and interact with local authorities. Local Russian-speaking communities did not yet exist on the requisite scale to take in more than a few newcomers. There was enormous pressure, and all the motivation you could want.
My family was among these immigrants (I was 6 years old at the time), and I’ve met hundreds or thousands of others. There is a very strong negative correlation of age and fluency in Hebrew, even today, after 18 years of immersion. People who immigrated at age 10-15 or younger are fluent speakers, have little to no accent, and it is very remarkable to meet an exception. Among people who immigrated as adults, most are fluent but make grammatical, pronunciation or spelling mistakes, or have vocabulary problems. Among people who immigrated at age ~~ 50-60 or older, many (I estimate at least 20-30%) never progressed beyond rudimentary skills necessary for e.g. shopping, cannot read or write fluently.
There is of course strong correlation between environment post immigration (school, work, non-Russian-speaking workplaces) and ability, but I’ve met enough such people to know that the causation goes both ways.
I suggest that causation operates via the very real change impact on motivation and the willingness to change one’s identity. 18 years of dedicated practice is enough time for nearly anyone to become an expert in nearly anything to a far greater degree than mere competence.
Studies find that adults actually learn languages faster than children do and older children faster than younger. Here is a more subtle investigation of how the motivation of adults interacts with circumstance and language in natural circumstances.
Possible confounding factors:
old people have higher discount rates (‘if I’m going to die next year, why bother?’)
less time to benefit from learning period (years, as opposed to many decades like a kid)
old people have less gain (both from #1 & #2 and because they have support structures which speak their native tongue—their relatives and friends)
old people are just stubborn and dislike the new country and its language (did the old people want to leave? Unlikely).
There’s motivation and then there’s motivation. Children are too young to respond to the requirement incorrectly enough to completely fail at it. If your System-2 must learn a new language, but you can still System-1 speak your native tongue within family or with friends, it is a different situation from where a child has no way of communicating at all, and communication is not just an instrumental requirement, it is a powerful instinct. Of course, some older adults will have damaged learning ability and won’t be able to learn a new language, but it’s an entirely different issue.
You’re saying all adults could learn a new language and become fluent if the motivation was on the level of “not being able to communicate with anyone at all”. Is there hard evidence of this? In particular, once such people achieve basic communication, do they reliably move on to fluency?