This still doesn't explain why intelligence is
intrinsic, or even the
nature of intelligence for it to be compatible with it being intrinsic. I personally believe intelligence is a
function of awareness and will. Learn to recognize those things that are important and focus on them and you will succeed, this is a
positive feedback loop that most identify.
Success, of which a component part is intelligence results primarily from selecting the right patterns of behaviour within appropriate situations. You cannot call a person stupid, that is incorrect. To say they made a mistake, or they are ignorant is more correct. If you can, then change some of the fundamental assumptions they have that force them to make mistakes and inhibit their behaviour.
No-one wants to fail, we just get lost in the maze of information that is presented to us day in and day out at an ever increasing rate. Intelligence is not intrinsic, we just pick up behavioural patterns from our parents and those around us, and they interact with genetic predispositions to certain modes of perception, and those factors determine our success.
Remember that, the next time someone calls you stupid. You aren't, they are just ignorant. If you want to change their minds, learn to change the way you look at things, and remember that whatever you are looking at right now, a side of it remains hidden.