[eikenberry]

Given that they use IQ as a measure also goes to show how little they understand the effects at this point. So take this all with a grain of salt. The best evidence at this point is that adolescent use has some effect on long term memory formation, but even that needs much more study to be understood it. Nothing in the brain works on a simple better/worse scale.

[riversflow]

Yeah, I’m highly skeptical that marijuana makes you legitimately more dumb. If I had to guess, I’d suspect that there are other factors that lead to this result. I’m skeptical because I have seen friends and acquaintances who were “dulled out” by drugs during this period of their life. While many of them were “heavy users” of marijuana, all of them were dulled from other psychotropic drugs(ecstasy being the big one), and most of them lost more than 6-8 IQ points. More like 20+ points.

If anything, I’d say that marijuana use tends to make the brain more doubtful, even of itself. In real life this is a mostly positive trait, but it is punished by the IQ test I think.