I agree with the first commenter on that page, though. Did they control at all for other factors? I'm sure sleep-dep is a much greater factor than dietary caffeine, and sleep-dep people probably drink more coffee.
There's actually some research that says that schizophrenics are prone to not only drinking booze but also coffee. Weird but easily googled. Makes you wonder about that guy who alway gets shouty when ordering at Starbucks.
Personally . . . I think I blame the crazy, then the sleep, then the habitualism (you get used to it, and that probably makes you more prone), and then the caffeine. Although there are certainly days when the caffeine level probably gets a little too high.
I think I mentioned this before, but . . . I have some of that Shower Shock caffeinated soap, but I've never unwrapped it. You can absorb caffeine through your skin much faster than through your digestive tract (hold not-too-hot coffee in your mouth if you want to get the caffeine out of it fastest), and I don't need to increase my odds of falling down in the shower. I always mean to get a soap dish and try it as hand soap, though.
Still. Potentially embarrassing. 'Can't sleep! Washed my hands!'
