Of bedbugs and metacognition


Doctor and blogger Stephen Novella talks a lot about "metacognition"—essentially, thinking about the way we think. In particular, he's interested in how our brains create the biases that prevent us from making accurate observations of the world, and often cause us to miss preventable problems until they're already happening. In a recent post, he uses the recent bedbug outbreaks as an example. These creatures aren't particularly dangerous to most people—but they are pretty annoying. And, more importantly, they're something we Westerners have come to associate with the bad hygiene of a time we thought we'd progressed beyond.

Novella doesn't talk about this, but, from my perspective, the driving force behind the bedbug "crisis" this summer seemed to be shame. Nobody wanted to be the kind of person who'd be subject to a bedbug infestation. It reminded me a lot of living in Alabama, where cockroaches were something that happened to dirty people—but Palmetto Bugs (really, just extra-large cockroaches) were what you called them when they weren't your fault. In reality, Birmingham just has a nice climate for roaches and, anytime it got remotely cool outside, they'd come on in. The bedbug situation is similar, Novella says. It has nothing to do with hygiene and everything to do with factors like an increase in long-distance travel, reduced use of the pesticide DDT, and bedbug adaptation
to that same pesticide.

My initial surprise at hearing this story, I think, reflects an inherent progressivist bias in our thinking. We tend to think of human history as making inexorable progress. This bias is reinforced, especially since the industrial revolution, by the fact that science and technology has been relentlessly progressive. The problem is in the default assumption that all change is progressive – whatever current system we have must be better than the old system because newer is better.

Human history, however, is more complex than our default assumptions. Sometimes history is regressive. And sometimes it is cyclical. Not all current trends will extrapolate indefinitely into the future. Today's fad is not always the wave of the future. In my mind bedbugs were a problem of pre- or early industrial societies, and were no longer an issue given modern hygiene and pest-control. I associated bedbugs with an earlier age, and it just seemed incongruous that they could return in the 21st century. But the details tell a different story.

[Of course] We shouldn't fall prey to assuming that because bedbugs are currently on the rise that they will continue to do so. Perhaps their return will turn out to be only a brief cycle, and then they will fade once again from our collective attention.

My takeaway from this is a reminder that you can't just extrapolate—one way or the other—from a pattern. Instead, to know what you're actually seeing, you have to use the pattern as a jumping off point, to start looking for causal mechanisms and evidence. Just because something happened in the past, doesn't mean that's what's happening now. But the opposite is just as true. The only way you know for sure is to examine the specific situation.

Neurologica:The Coming Bedbug Plague