Do you think there is a direct correlation between success in academics and the ability to articulate yourself?

I have always had a theory, that if I had no ability to speak a language, I would think in a completely different way. I think in english. I problem solve in english. My memories start, around the time I learned to talk.
Is this the point we become self aware?
Do you believe that people who are forced to use correct grammar and encouraged to learn new words are given a foundation to learn easily the rest of their lives?
Is it just a coincidence?
Do you have any other thoughts on this matter?