Sunday, April 1, 2012

Don't take it personal, kid

Over at reddit a few days ago, there was this thread where a guy talks about how his daughter has cerebral palsy, and now at age three is doing really well.

But what I found interesting was part of the title:
When she was born doctors said she would never walk, talk and would probably need to be institutionalized.
I always find this a strange response. If you want to see what I mean, compare it to an alternative formulation:
She's doing incredibly well, given her initial condition made it unlikely that she'd be able to walk or talk, and probably would have needed to be institutionalised
I don't want to pick on this guy - I'm really glad his daughter is doing so well. But I find it an interesting example of a particular mindset.

For some reason, people seem to really like the narrative 'and then the doctor [delivered bad news], but he was totally wrong!'.

It's not enough that things turned out better than expected. Apparently there's an extra sweetness to proving wrong an expert who delivered negative news.

My best guess is that this comes from a combination of:

a) A general lingering dislike of people who deliver bad news

b) A particular dislike of people who deliver bad news that turns out to be wrong, even if it was probabilistically correct at the time, and

c) A sense that medical conditions have substantial scope for self-fulfilling prophesies: if you treat someone like they're disabled, they'll end up disabled, but if you treat them like a normal person, they'll end up comparatively more normal, even if not perfectly able-bodied.

The first one I can't relate to at all. The medical profession is the last place you want to start shooting the messenger - if you in fact have cancer, you're going to be a hell of a lot better off knowing that and starting chemo than pretending that you've got something else.

The second one I can't really relate to much more. I can understand getting irritated at advice that was bad ex-ante. But that doesn't quite explain it. As a layman, you'll probably have very little idea whether the advice was wrong ex-ante, or right ex-ante but you just ended up in the odd end of the distribution. e.g. Most people born with cerebral palsy won't be able to walk, but your daughter ended up as one of the lucky ones.

More importantly, would you be equally mad with a doctor who delivered ex-ante advice that was correct but ended up being too optimistic? "The doctors said she'd probably be able to walk just fine, but she can't." Unless you'd be equally bothered by this one, there's still something funny going on.

The third one may have some merit, but I don't know how much. I tend to be slightly skeptical (without any particular evidentiary basis) only because it sounds too much like wishful thinking - if we only act like there isn't a problem, there won't be a problem!

If you want the extreme opposite view, let me present you the great James Bagian, a man who was meant to be on the Challenger Space Shuttle but was substituted out shortly before the mission. He declined to wax lyrical about beating the odds or pretend to be shocked that the outcome was as bad as it was:
Was I sad that it happened? Of course. Was I surprised? Not really. I knew it was going to happen sooner or later—and not that much later. At the time, the loss rate was about 4 percent, or one in 25 missions. Challenger was the 25th mission. That's not how statistics works, of course—it's not like you're guaranteed to have 24 good flights and then one bad one, it just happened that way in this case—but still, you think we're going to fly a bunch of missions with a 4 percent failure rate and not have any failures? You gotta be kidding.
I'm going to go out on a limb and predict that a man who can get in a space shuttle and understand exactly what a 4% probability of the thing exploding means is not somebody inclined to blame a doctor for a negative diagnosis that turned out to be wrong. As indeed evidenced by the entire approach he takes in his current job - figuring out how to reduce medical errors.

As always, sign me up with James Bagian.

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