Ferreting their worth in waste, I Googled for "wasted intelligence" and "wasted intellect". The count is 127 and 37 respectively. Much of the "wasted intelligence" phrase is properly used and gives an indication of intelligence present but not applied/improperly applied whereas much of wasted intellect looks like a misfit, and in most cases the writers' attempt is to express wasted application of intellect rather than the intellect itself. In brief, it's very difficult to think of how intellect can be wasted the way intelligence can be. Therefore intellect = intelligence + wisdom