Just on the sports thing, I think the difference between talking positively about sport - or, say, musical - prowess compared to giftedness is that the effort for reward is obvious. Everyone knows that to be a great sports star or an outstanding musician requires a massive amount of effort. This is not so apparent with intelligence (I am not saying that honing intelligence in to something meaningful or useful doesn't require effort, just that it doesn't look like it requires effort and in fact you reap many benefits of intelligence without having to work at it).
Most people are quite happy to let the sports star spend their day in the gym, in the pool, on the track etc, etc. They have no interest in do those things themselves and so there's no threat. Same with music, dance, art, etc it's apparent how much effort is involved and most people simply aren't interested in dedicating that amount of effort to any task. So the fact that someone else wants to - and the fact that what is produced by sports stars etc is usually perceived to be of value by the broader community - that talent is viewed positively (this is my theory - happy to have holes found in it).
But if you're smarter than someone then that's much less quantifiable. You haven't put any effort in to being smarter, it's not clear what that actually means, there is no apparent broader value to your smartness (unless you're a Steve Jobs or a Bill Gates - ideally you will have flunked out of college) and frankly it's all a bit threatening. And with your smartness you want to do boring things like stick your head in a physics text book or study Greek mythology or - quick intake of breath - maths! Just for fun! That is just plain weird and probably unhealthy... (unlike sport - then you're a role model, given the obesity crisis and all...)
