[DCWildcat]

I doubt it heightens our overall intelligence. It does, as you pointed out, probably lead to a few things:

1) A more fit brain that "thinks harder." There is a difference between soft, shallow thinking and strong, penetrating thinking, and every human smart or not has this capacity. Unfortunately, in my opinion, some of us are conditioned against it (i.e., in households/religions/etc. demanding strict obedience).

2) More efficient thinking. You have to make all of your decisions in a relatively quick timeframe, especially when multitabling. In marginal situations, practice with mental checklists, rather than panic, become important.

3) Most importantly, it helps us become better critical thinkers. For one, it helps us identify mistakes better (plugging leaks, reviewing others' play). But more so--and this is huge--it teaches us the relative value of mistakes. Some mistakes are worse than others. Recognizing not only the existence of errors but the relative magnitude of those errors is crucial for critical thinking, and its absence is one of the easiest ways to sniff out dumb folk.