It says it right in the article:
Basically, the whole focus is people who started using before their brains fully matured. FWIW I agree fully with the thought that it's not how much you toke but how much you actually use your brain that matters. IME, as long as you fight the negative effects you can push through them and be just as smart as you want to be.
While the average age participants started using marijuana was 16, some began as young as 10 or 11 and were more seriously affected.
Basically, the whole focus is people who started using before their brains fully matured. FWIW I agree fully with the thought that it's not how much you toke but how much you actually use your brain that matters. IME, as long as you fight the negative effects you can push through them and be just as smart as you want to be.
