Intelligence
Intelligence is the state of associating or discriminating things (concepts, objects etc). For example, a person who naturally associates clouds with rain is more intelligent than one who doesn't. Or also, a person who discriminates between a storm cloud and a fair weather cloud is more intelligent than one who doesn't.
Stupidity is not the lack of intelligence, but a false intelligence, the result of a bad teacher.
Naivete (or innocence) is not stupidity, but the beginning of intelligence.
The difference between naivete and stupidity can be clarified with an understanding of the hunter archetype. Intelligence is a quarry for the hunter. It has the same paradox as anything properly hunted. Specifically the more you are hunting "it" (as something you have defined), the less success the hunt will have. It's like if you see that you have 5 fingers and you say "that is good" and "I want that". How do you improve the "fiveness" of your fingers? Whatever you do, it won't end well. The same goes ultimately for everything, but in this case it goes for intelligence.
So does that mean naivete is good? No. It means you have it (naivete) while you have it and when you don't have it, it's gone (to whatever extent). But improperly hunting intelligence will not remove your naivete, it will only change it to stupidity.