Very intelligent people are people who have a powerful and active frontal brain lobe. Or more properly, a strong prefrontal cortex. This brings the capacity of deciding (or more precisely finding paths) brightly. They usually do the things that work.
But there’s a wrinkle in that picture. Brains are not mystical, transcendental, independent decision makers. Brains are physical systems. If a brain chooses anything, that means a positive feedback device inside the brain has been activated. This person has a given pattern up there that tries to repeat itself, a brain process that enhances its own chances of happening again. This is basically undistinguishable from an addiction.
In fact, we should think about the brain as a complex interweave of addictions, and about beliefs as addictions. Chemically speaking, that’s what they are.
If a person is intelligent, she likely has some of those positive feedback things about using her noodles. She likes to think.
The reason being that, just as no one gets strong without using their muscles, you can’t get intelligent without practising thinking. A person does not begin to like thinking because she gets intelligent, she will get intelligent if she starts to like it.
If she has a positive feedback loop about using her brain, she will tend to put herself in situations where she has to. Not only she will do what makes her happy, she will also do what makes her brain active and challenged. In the long run, this means she’ll get used to creating problems to herself! Intelligence, then, just like Truth or Science or Love or anything else, is a trade-off — and we should deal it with care.