Blink: Is Information Destructive?

This is the first time I've mentioned Malcolm Gladwell's Blink, but it won't be the last. According to Gladwell's site, "It's ... about rapid cognition, about the kind of thinking that happens in a blink of an eye." And you should get it (audio, paper). Heck, it's one of the only books where the support points alone are worth your time (e.g. insanely detailed research leading to fast, simple, accurate forecasts of which married couples stay married). I'm going to start off with one of Gladwell's relatively minor points: information can be destructive. Most of us are info hounds. The idea that more can be less in something so fundamental seems like silly folklore. Perhaps more info can bog things down a bit, but "it's not really going to make things worse in the real world." And that's where Blink changed my thinking. Gladwell uses a long example about the use of information during war. "When bullets are flying," his objects of study assert, "scenario planning bogs down thinking and filters out the really great (and typically unprovable) ideas." But another example is even more compelling: Doctor diagnosis. Turns out that additional tests and data don't objectively improve doc's diagnosis accuracy. Yep, that alone is worth repeating: more data doesn't improve diagnosis. (OK, eliminate the extremes of diagnosing over the phone without seeing the patient, etc.) Gladwell cites research on this which, if you believe he's not confused or purposely deceaving, is compelling. But if this is where the story ended, it would just be an economic issue. You'd be taking tests and not getting better results. The bill gets bigger. But what's destructive? Ah, that's the rub. The docs who diagnosed with more tests and data were more sure of their diagnosis. They were more confident. Mind you, they were not more accurate. They just thought they were. And this is classic "null hypothesis" territory. If you feel more confident, it takes more to change your mind. If you feel more confident, you stop questioning. If you feel more confident, you will be slower to realize when you are wrong. And that's destructive. There is zero question that if Gladwell isn't fudging results, additional info can be destructive. And this isn't a bizarre, unlikely example. It's an example in field that all of us might one day have a personal interest in accuracy.