To be intelligent is a matter of choice. The person needs to choose to be intelligent. Also, to be intelligent the person basically only needs to choose.
Unhappily, one cannot be intelligent about quantum physics without being intelligent about picking socks to wear each day.
At first, this might sound as nonsense. As the world is chock-full of dumb people, it would seem that being intelligent would be hard stuff, that it must require something that not everyone has (like talent, inborn qualities, a calling from Bog or something like that).
I’ll concede that likely there are numerous other factors that influence total intelligence, specially on extreme cases (geniuses or retards). But the choice factor does have a much more perceptible effect than those others, because after all it is one you could (but wouldn’t — see below) do something about.
The real point is that being intelligent is not having the capacity of making the right choices. Intelligent people make lots of wrong choices, although having a unexpectedly high level of right ones made is certainly one side-effect of being intelligent. Being intelligent is about making the intelligent choices — and this is very different.
One of the most striking differences between those two is that the intelligent person will only very rarely be sure of anything. When there is 92.7% chance of something, the intelligent person is the one who asks “and what about those other 7.3%?” And actually most intelligent people can very quickly become annoying for questioning what does not make any difference (and learn to fake not doing that out of desire for their peer’s love and affection).
I do not mean to say that intelligence is disregard for what we could call “important things”™, nor that intelligent people will always be considering abstract, vague, distant, and marginal issues. Not at all. Trying to find what is truly relevant in any given circumstance is definitely an intelligent behavior. But the intelligent person is the one who will also ask: “and what else?”
I do not mean to make a definition of intelligence here. In other words, i am not implying that you could check whether or not someone is intelligent by measuring how much he chooses “intelligent” choices.
Intelligent people will already have got that from what it i said so far, but: in my way of seeing things, to choose to be intelligent is not the right choice. It is merely one choice, amongst others. Many, many times, the intelligent choice is also the more costly one, the most boring, the less cool. If it is the right one or not varies from person to person, from circumstance to circumstance.