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.

Glenn W. Bowen (mail):
They're not getting enough dolphin:

Puddyng of purpaysse. Take þe Blode of hym, &þe grece of hym self, &Ote-mele, &Salt, &Pepir, &Gyngere, &melle þese to-gederys wel, &þan putte þis in þe Gutte of þe purays, &þan lat it seþe esyli, &not hard, a good whylys; &þan take hym vppe, &broyle hym a lytil, &þan serue forth.
8.22.2009 6:54pm
troll_dc2 (mail):
So the bottom line is that all single-factor explanations are inadequate most of the time.
8.22.2009 7:32pm
Leo Marvin (mail):
No, it's that everyone's a reductionist (irony intended).
8.22.2009 8:39pm
einhverfr (mail) (www):
Glen Bowan wins the thread!
8.22.2009 8:57pm
n_shapero (mail):
The ideas that being "obese" is a personal choice or that it results from lack of "will power" are among the most pernicious of falsehoods that I have come across in this particular domain. A few "small" facts:

1. Several years ago, the standards for what constituted "obese" were redefined, eliminating the weights for the standard and large body types, leaving only the thin/small body type (automatically adding some 20% to the numbers of people declared "obese" without changing anyone's body shape, or weight).

2. The BMI (body mass indicator), which was invented between 1830 and 1850 by the Belgian polymath Adolphe Quetelet during the course of developing "social physics", and is still used today to determine "obesity" does not have a sound scientific basis (any more than phrenology does). It is controversial statistical measurement not found to provide a significant statistical correlation with true health/body-fat factors. When I was in grad school, and regularly working out (free weights) I dropped to around 8% fat. I was at my current height, and I weighed close to 185 pounds -- very little of it fat (the measurement was made in a water tank -- I had access to LOTS of goodies back then). My "BMI" proper weight, however, was and is 140 pounds (according to the BMI fanatics, that is). By the BMI measurement I was, at the time, 45/140 = 32% overweight (the term mobidly obese is applied to any male who is more than 50% over their "ideal" weight, any male more than 25% over their "ideal" weight is obese). I was never in better physical shape (either before or after that time) but I was "obese" by the "modern" standard.

If someone tells me that obesity can be a problem, and we ought to investigate it (due to secondary health problems, like type II diabetes which statistically IS on the rise in this country), I'd agree with them. But anyone expecting there to be a simple answer, with a simple formula for "proper weight" is asking for something that they are just not going to find. Math is simple; the universe, however, is not (ask anyone who spends their life studying physics or BIOchemistry).

-- N. C. Shapero, who has spent several decades as a working engineer, dealing with laws made by God and not by Man.
8.22.2009 9:53pm
Tony Zirkle (mail) (www):
Sexual impurity leads to depresssion which aggravates obesity.
8.22.2009 11:11pm
Brian K (mail):
Sexual impurity leads to depresssion which aggravates obesity.

sex is very good exercise...the obese "impure" just aren't having enough of it.
8.22.2009 11:26pm
einhverfr (mail) (www):

A lot of our health sciences are pretty much junk science anyway. The BMI thing is rather stupid and there are better measurements. For example waist to height ratio is a better indicator of most of these problems than anything else. This has been closely looked at but doesn't get a lot of attention.

Nutrition though is another good example. I have spent more time arguing with nutritionists about all sorts of things from hazards of overuse of Omega-3 fatty acids (epidemiology shows are connected to cerebral haemorrhage) to questions such as whether the food pyramid recommends too many carbs (I think it does). I was in favor of butter over margarine long before the nutritionist community latched onto the transfat craze (and I still don't trust margarine).

These things are closely connected, but what is certain is that we aren't doing anyone favors by clouding the waters with junk science.
8.23.2009 12:48am
Melancton Smith:
As a species we are something like 150,000 years old. Only in the past 10,000 years or less have we had access to huge amounts of simple sugars and other high glycemic foods. We simply aren't designed to consume those foods. The food industry keeps putting more and more sugar into more and more of its products. And we keep swilling it down.

Eat more whole foods and less boxed food, in a nutshell and avoid high fructose corn syrup like the plague.
8.23.2009 12:54am
John Moore (www):
The health care debate has caused a number of ideas to float around about obesity. Most are, indeed, simplistic. (reductionist seems an inappropriate term here, btw).

The idea that a fine for obesity (which is exactly equivalent to a financial reward for not being obese) will make any difference is absurd.

Does anyone thing that fat people like being fat (leaving aside a few subcultures)? We see lots of fat female teenagers, and I'd bet every one of them goes through continuous anguish about it, given the social consequences.

Obviously, as suggested in this thread, strong factors are at work.

As one who has struggled with weight for decades, but who successfully quit cigarette smoking cold turkey (back when nicotine patches were still illegal thanks to the FDA), I know that this is a difficult issue. Cigarettes are clearly and directly strongly physiologically and psychologically addictive, yet smoking cessation has a dramatically higher success rate than weight reduction programs.

With biology, nothing is simple. The same applies to psychology.
8.23.2009 1:08am
DiversityHire (mail):
One of the best reminders of the limits of reductionism is Jacob Bronowski's The Origins of Knowledge and Imagination. He talks about the difference between descriptions and explanations, how reductive methods have succeeded in finer and finer descriptive scientific theories that provide less explanation (w/in the higher level) of the systems thus described. Another interesting perspective on projecting-from/reasoning-about the reductive model back to the higher-level abstraction is Sherry Turkle's Simulation and its Discontents which touches on confusing the model with the modeled system. It seems there is an irresistible urge to apply the fruits of one's reductionist explorations upward, as broadly as possible.
8.23.2009 1:16am
John Moore (www):
The original author erred in calling the trend "reductionism" - since reductionism is a theory that your can explain everything by understanding its tiniest parts (as shown most dramatically in physics).

The author is really complaining of a trend toward over-simplification, a very different thing.
8.23.2009 1:30am
Cornellian (mail):
No one I know is starving, but no one is ever full

This implies a false dichotomy. Being thin doesn't require being hungry all the time, or even most of the time.
8.23.2009 3:26am
Houston Lawyer:
The current wave of obesity is clearly driven by behavior. I keep waiting on the next set of anti-discrimination laws making criminals out of those who might prefer the thin or toned.

That being said, if I could come up with a program that guaranteed permanent weight loss, I'd have more money than Bill Gates.
8.23.2009 9:53am
jb9054 (mail):
C'mon guys, lets stop all the navel gazing and rent-seeking. There is such a thing as obesity, however you want to define it, it is increasing in the USA (anyone really want to argue against that?), and there is a guaranteed effective way of overcoming it- eat less, move more. The problem is that while the guaranteed effective way of overcoming obesity works 100% of the time, it's not fun, so in go the rent-seekers, people who make a buck or 2 trying to ease the transaction, trying to fool the obese into thinking that there really is a fun easy way to lose weight. We are hardwired to retain nutrients to allow survival in lean times, but now that lean times essentially do not occur in our society, up go the waistlines. The average sized human needs 1500-2500 calories per day to maintain function, depending on activity level, and many Americans get there by 2:00 every afternoon, so whatever they have for supper is excess that goes to adipose tissue. (According to, the heavily promoted Angus Deluxe sandwich, with medium fries and Coke, provides 1340 calories). 3500 calories = 1 lb. of fat, so if you consume 100 Cal per day over your expenditures, you will gain just under 1 lb. per month. Doesn't sound like much, just 10lb per year- yikes!
If a person is overweight/obese/fluffy/plus-size, it comes down to thermodynamics. If that person eats less calories than he burns during daily activity, he will lose weight. As Hillel said in another context, the rest is commentary.
8.23.2009 11:53am
Melancton Smith:
All calories are not equal. Sugars and sugar-like foods (look through the supermarket and count how many products have sugar) tend to make you hungrier. It is a vicious cycle that ends in obesity, diabetes and general ill health.

If we are going to talk about healthcare reform, why not figure out how to fund disease prevention? The problem is that disease management is far to profitable.
8.23.2009 12:17pm
einhverfr (mail) (www):
John Moore:

I agree with your points. However, one idea that has been floated that I think state governments should consider is a set of taxes on things which are likely to unduly contribute to obesity.

For example, make frozen dinners taxable at the same rate as restaurant take-out.

There are all sorts of reasons the Federal Government shouldn't take this up. However I do think the state governments can apply some simple, fair rules relating to sales tax on food.

However, if we want a single libertarian strategy to deal with the problem, I have one: Eliminate farm subsidies. IMO these contribute to obesity in our country and starvation in developing countries.
8.23.2009 2:53pm
Corwin (mail):
I commented on another blog (I think it's called Pandagon) where people critiqued BMI. It's not perfect.Neither is Newton's Theory of Gravity. But both are very good. I'm an authour in a study on weight loss and DM II. BAsically, it seems several meds,including some used for other conditions will decrease appetite/cut weight for a period of nearly a year. Then,no more effect.We're trying to see if we can link exercise into the program as a way of keeping long term gains.And I want to close by saying I ran my 200 meter sprints today.Then followed with a chocolate covered cone.
BTW, the best new med for weight loss(accomplia) didn't make it by the FDA. It was also damn good for smoking cessation. And for raising good cholesterol. DId I mention the FDA nixed it?
8.23.2009 3:38pm
Assistant Village Idiot (mail) (www):
That was quick, eh KA? Try to talk about an obesity discussion as an example of a logical difficulty, and we are off and running into discussion of the example instead of the topic. Particularly good examples of the flaw you describe are illustrated by Melancton Smith's comments.

Steven Pinker writes a great deal about the brain's use of shortcuts for efficiency (of storage, especially) and the dangers inherent in that efficiency. Try The Stuff of Thought first, I suggest. Shorter Pinker: we use shortcuts because we would be absolutely unable to navigate through the day if we didn't oversimplify 99% of what comes by us.
8.23.2009 5:46pm
Mac (mail):

BTW, the best new med for weight loss(accomplia) didn't make it by the FDA. It was also damn good for smoking cessation. And for raising good cholesterol. DId I mention the FDA nixed it?

What was it?
8.23.2009 9:16pm
Mac (mail):
There are reputable studies suggesting that sugar substitutes are the culprit and not sugar. In a recent study, lab rats who ate the substitute ate more and gained more weight than the rats who ate sugar. The author says much more research is necessary before we draw any conclusions. He posits that maybe something in the substitute is turning on our starvation gene.

It does seem that ever since sugar substitutes and low fat and fat substitute products have hit the market, we are getting fatter and fatter.

It is at lest possible there is a problem with these products.

It would be ironic if the Government taxes products with sugar as opposed to sugar substitutes and thus encourages the use of products that, in reality, may be causing the obesity problem.

Another reason the government should keep its nose out of our lives.

Speaking of government subsidies, did you see where 40% of the tart cherry crop is being forced by our Gov. to be allowed to rot in order to keep the price of cherries high? There is something very wrong with this picture.
8.23.2009 9:25pm
Donna B. (mail) (www):
I'm living proof that diets don't work. I had the bariatric surgery common at the time 15+ years ago and I now weigh more than I did when I had it.

Decreasing the size of the stomach makes one more likely to seek calories that are easy to digest. These are carbs. I have a problem getting enough protein in my diet which has led to numerous health problems I would not have had otherwise.

Too many doctors have suggested that I convert my VBG to an RNY. Yet RNY procedures lead to many more deaths than other procedures.
8.24.2009 4:44am

Post as: [Register] [Log In]

Remember info?

If you have a comment about spelling, typos, or format errors, please e-mail the poster directly rather than posting a comment.

Comment Policy: We reserve the right to edit or delete comments, and in extreme cases to ban commenters, at our discretion. Comments must be relevant and civil (and, especially, free of name-calling). We think of comment threads like dinner parties at our homes. If you make the party unpleasant for us or for others, we'd rather you went elsewhere. We're happy to see a wide range of viewpoints, but we want all of them to be expressed as politely as possible.

We realize that such a comment policy can never be evenly enforced, because we can't possibly monitor every comment equally well. Hundreds of comments are posted every day here, and we don't read them all. Those we read, we read with different degrees of attention, and in different moods. We try to be fair, but we make no promises.

And remember, it's a big Internet. If you think we were mistaken in removing your post (or, in extreme cases, in removing you) -- or if you prefer a more free-for-all approach -- there are surely plenty of ways you can still get your views out.