I don't think it relates to intelligence at all. U either have it or u don't. Being intelligent can mean many different things. Usually marijuana stimulates the brain, or the exact opposite. So u can have two different results. I find it helpful to learn things while high, and to do a lot of pre-thinking while stoned, when it comes to taking test and such its def. better to have a clear mind. I do a lot of abstract and creative thinking. For instance one of my main hobbies is R/c's, while researching and building things being high is great, and always gets me the best results. When it comes time to go fly my heli or planes, i def. need a clear mind so i don't dumb thumb it into the ground.