> His claim was that receptive vocabulary in grade school children was the single best predictor that was known for their IQ and tests scores in high school and presumably beyond.
This isn't true. For example, IQ as a 20 year old is a better predictor of IQ in high school than receptive vocabulary in grade school is. It happens that it's hard to observe the IQ at age 20 of a child who isn't 20 yet, but that doesn't change the strength of the predictor.
> But having been exposed to a lot of vocabulary when you're young seems to be a good thing.
You provide no support for this other than the fact that a large vocabulary at a young age is indicative of a high IQ later. However, a large vocabulary later is also indicative of a high IQ later. Applying the same logic, you should conclude that being exposed to a lot of vocabulary when you're old is just as good (if not better!).
If you don't think studying vocabulary as an adult will get you very far, why do you think studying it as a child is different?
This isn't true. For example, IQ as a 20 year old is a better predictor of IQ in high school than receptive vocabulary in grade school is. It happens that it's hard to observe the IQ at age 20 of a child who isn't 20 yet, but that doesn't change the strength of the predictor.
A predictor is something that you can measure and make predictions from in advance. Therefore by definition the eventual IQ at age 20 is not a predictor of future IQ for grade school children.
Now can we dispense with the semantic games?
> But having been exposed to a lot of vocabulary when you're young seems to be a good thing.
You provide no support for this other than the fact that a large vocabulary at a young age is indicative of a high IQ later. However, a large vocabulary later is also indicative of a high IQ later. Applying the same logic, you should conclude that being exposed to a lot of vocabulary when you're old is just as good (if not better!).
Not indicative, predictive.
Receptive vocabulary is part of IQ. So of course having a large receptive vocabulary helps your IQ. But children with a large receptive vocabulary when young tend to have future increases in other mental abilities. By contrast children who show high abilities in other areas when young do not show the same improvement.
The theory that I was told is that children who can understand complex verbal things find it easier to learn from our education system. And children can't learn to use complex language without first understanding it.
If you don't think studying vocabulary as an adult will get you very far, why do you think studying it as a child is different?
The research on development that I've encountered indicate that there are specific developmental periods where we are particularly receptive, and where our abilities tend to increase suddenly. Starting with a large receptive vocabulary seems to position you well to make the most of these.
When you're older, studying vocabulary is unlikely to be bad for you. But you don't have the same developmental spurts ahead to try to maximize. Furthermore vocabulary is less likely to be a barrier for adults than children.
For example my son right now loves ants. He is learning things about ants that other children his age would have trouble with because he understands words they don't. But he doesn't have a better vocabulary than most adults. Any literate adult who wants to learn what he is learning about ants can simply pick up material on ants and read it.
This isn't true. For example, IQ as a 20 year old is a better predictor of IQ in high school than receptive vocabulary in grade school is. It happens that it's hard to observe the IQ at age 20 of a child who isn't 20 yet, but that doesn't change the strength of the predictor.
> But having been exposed to a lot of vocabulary when you're young seems to be a good thing.
You provide no support for this other than the fact that a large vocabulary at a young age is indicative of a high IQ later. However, a large vocabulary later is also indicative of a high IQ later. Applying the same logic, you should conclude that being exposed to a lot of vocabulary when you're old is just as good (if not better!).
If you don't think studying vocabulary as an adult will get you very far, why do you think studying it as a child is different?