Four Modes of Reductionist Explanation:

Over at Asymmetrical Information, Megan McArdle posts an email from a reader responding to a series of posts on the causes and solutions of obesity. The email is bracing and provocative, written from my home town of LA; here is a bit of the email to McArdle:

As someone who works in the entertainment industry in Los Angeles--land of the perfect body--I totally agree that government pressure will do nothing to make people lose weight. People will only give up one pleasure in exchange for a more intense pleasure. And if you're poor and miserable, and eating is the high point of your life, you'll always reach for the cheetos.

I suspect the only way people will change their behavior is a sudden desire to move up the social ladder. Being thin and attractive gives you a competitive edge, especially if you live in a city with lots of talented people. The moment someone I know suddenly gets ambitious, or makes partner, or needs investors, they start losing weight. In California, being fat will hurt any career, whether you're a doctor, lawyer or accountant. We all take our cues from television/movie industry and the message is clear: you must be sexually appealing, no matter what you do. And so we tune out the Dominos commercials and reach for the tuna. Thank God for sushi, or we'd all go crazy.

No one I know is starving, but no one is ever full ...

I'm not quoting this for the substance here or even for the topic of (anti-) obesity as public policy. Rather, I was struck by the first four comments on the post. With a little free interpretation, they offer an intriguing, accidental, array of the forms of explanation that are currently on intellectual offer in our culture more broadly. Not comprehensive, I'm sure, and I have applied some interpetive arm-twisting. But consider (and I'm not picking on people here; all of us engage in most of these forms of explanation freely, and not necessarily inaccurately by any means):

Comment One: The Political. Granted, it is via a skeptical view. Freely restated, it says (more or less): California can't politically govern itself, so why should anyone pay attention to its views on obesity and thinness? I'll take that as a sort of negative political explanation; if it could politically govern itself, then we might have reason to pay attention to what it thinks is the way to combat obesity.

Comment Two: The Cultural. Citing to Virginia Postrel's excellent book on this topic, and the theme of which is, "smart is good, smart and pretty are better."

Comment Three: The Biological. And specifically, the biologically, evolutionarily hardwired - overcoming obesity in LA requires finding a pleasure more intense than eating. Though this comment mingles quickly - as happens in real life too - into the Cultural, because the pleasures that are more intense than eating are not merely physical, but cultural and social - fame, glory, etc., not just sex and mating.

Comment Four: The Economic. And specifically financial - an explanation from the discounted value of future pleasures and, in effect, a NPV of eat-now-to-obesity versus all the other great things LA has to offer provided one stays thin into the future.

I suppose it is in the nature of explanation that, methodologically at least, it strives to be simpler than the phenomenon being explained - Occam's Razor and all that. But there is no a priori reason why that should be the case, and often - as medicine, chemistry, physics, and other physical sciences have shown over the ages - the actual explanation is unimaginably complex. But these comments illustrate a general tendency toward certain well-trod paths these days toward reductionism. I share it - and I bet you do too. It is far from being a bad thing, of course, provided we keep the limits of reduction methodologically in bounds. We share a desire to model potentially complicated things with simple systems that, true, have often served well in other matters. But when I look at actual science of so many things, actual explanations are fantastically complicated and overlapping, not really reductionist at all.