Question:
A friend who adopted two Russian children ten years ago when they were five says their English skills are permanently deficient because they learned English "too late". (Their English sounds fine to me.)
Do you think that an adult who can't read is in the same position as a five year old? Thinks like a five year old, has a five year old's experience of the world and the printed page?
Answer:
If_ those kids have troubles with their English it is not because they were five when they started learning it. Their pronunciation might be ever so slightly affected, because their speech muscles would have imprinted on Russian sounds, but probably not to a disabling degree. By the age of fifteen, with ten years of English learning, any problems they have are special, specific ones having to do with their own unique experiences and learning styles and conditions. Not having met the kids in question, I can't say what's really going on with them, but I will point out that moving to a new community at the age of five is traumatic: getting a new family at the age of five is traumatic: getting parents who speak a new language is traumatic: and that trauma does things to people's learning. All sorts of things, from the subtle to the massive, in predicatble and unpredictable ways.
No, not necessarily. There are lots of life experiences which would cause a person to be relatively illiterate without their being any mental deficiency at all.
"Mental age" is, as you indicated, a weird old-fashioned approximation of what's going on, which isn't that.
