I think intelligence and attitude are both multipliers. The difference is, if you glorify attitude (to yourself) it can help you improve your attitude. Glorifying intelligence won't improve your intelligence so easily.
However, we programmers must fight egotism and arrogance. The danger is that in forgetting that we are fallible and were new programmers once, we commit a grave error. We're all shortsighted at one time, or another--unless we fall prey to egotism.
