They don’t. The social and personal influences to encourage such efforts are not all that common. Most adults don’t master most areas of expertise.
I assert that most people can master almost anything if they spend 4 hours every day in dedicated practice for 10 years (ref). I do doubt that most people will perform such a remarkable feat (papers in the same reference traced much of the heritability of expert talent to inherited motivational factors.)
Still in the end most children will learn their first language faster than most adults will learn a second.
They don’t. The social and personal influences to encourage such efforts are not all that common. Most adults don’t master most areas of expertise.
I assert that most people can master almost anything if they spend 4 hours every day in dedicated practice for 10 years (ref). I do doubt that most people will perform such a remarkable feat (papers in the same reference traced much of the heritability of expert talent to inherited motivational factors.)
Still in the end most children will learn their first language faster than most adults will learn a second.