Intelligence I can tell you from my experience. A lot of people say I'm really smart. Yet when I take an online IQ test usually score average. Either people mistakenly think I'm intelligent or online IQ tests are unreliable, or both. I've had a rabbi call me a dumbbell. I had a friend say "your not smart". Another friend told me "you strike me as a really dumb person", "you say stupid things". On the other hand, I had professors call me really bright on many occasions. I have a 3.9 GPA -- at a community college. If there is way to know whether someone is intelligent by just knowing them at least half the people who knew me got it wrong.