There’s a story that (some) physicists and science reporters seem to like, which is the idea that some clever mathematician or physicist can derive universal laws of social behavior.
It’s time to tell you all: Hari Seldon never existed.
Here’s what I think of these stories of physicists who discover the laws of society. I think they’re comparable to the stories we used to hear about, of the eccentric inventor who built a car engine that got 200 mpg, or ran on water, but was then suppressed by GM because they couldn’t handle the competition. Or, if we want go Heinlein, some guy who builds a time machine in his garage out of random spare parts.
Or maybe I should put it in a way that everyone can understand. Look at Richard Feynman, master swordsman and physicist, the guy who was so much smarter and more charming than everyone else, the guy who bragged that when he took up biology as a hobby he could do better than the biologists, who bragged that when he took up painting as a hobby he was an awesome painter. Even Richard Feynman did not think he could discover laws of social behavior. Sure, maybe he had better things to do. But, just maybe, maybe . . . he realized it wasn’t gonna happen.
I was reminded of this recently when Peter Dodds pointed me to this news article by Nathan Collins, entitled “Physics Predicts U.S. Voting Patterns”:
Building on theories used to describe magnets, scientists have put together a model that captures something very different: voting patterns in U.S. presidential elections. . . . For example, a person who voted Republican in one election and lives in a politically neutral county but works in a heavily Democratic county would likely vote for a Democrat in the next election. . . . the researchers focused on the distribution of Republican margins of victory across U.S. counties as well as how correlations between two counties’ vote shares changed with the distance separating them, quantities more commonly used to describe the transition from a demagnetized block of iron to a magnetized one. . . . the researchers predicted a bell curve distribution of county-level margins of victory and surprisingly long-range correlations between counties; that suggests that some counties, at least, could feel the effects of social pressures in counties on the other side of the nation, they report this month in Physical Review Letters. What’s more, those patterns were a close match to the actual election data . . .
I disagree with this last claim. Their model seems to reproduce a normal distribution of county-level vote shares with spatial correlation. All the stuff about magnets and social interactions and a “noisy diffusive process” and “anysotropic coupling topology” are pretty much irrelevant.
The link above goes to an abstract only, but a quick search revealed the preprint, Is the Voter Model a model for voters?, by Juan Fernández-Gracia, Krzysztof Suchecki, José Ramasco, Maxi San Miguel, and Víctor Eguíluz. So you can read it yourself if you’d like (but I don’t recommend it).
Its a bit sad to see Science and Physical Review Letters falling for this sort of thing, but I guess the story is so appealing they just can’t help it. It’s a great narrative, that the laws of social nature are just out there, waiting to be figured out by some physicist.
The big picture
Maybe it would help to explain what I’m not saying here. I’m not saying that outsiders can’t or shouldn’t make contributions to social science, nor am I saying that complicated mathematical models from physical science shouldn’t be used to model social behavior, voting included.
Indeed, I myself am a former physicist, and in 2002 I published a paper (with Jonathan Katz and Francis Tuerlinckx) entitled, “The Mathematics and Statistics of Voting Power,” reproducing certain features of elections using stochastic processes defined on a tree of voters. In retrospect, I think maybe this paper could’ve been published in a physics journal! One of the models even has a phase transition—it’s based on the Ising model from quantum physics—and we have tons of math (see, for example, pages 430 and 432 of the linked paper). So it’s not that it can’t be done, but the work has to be evaluated on its own terms. The physics connection isn’t enough on its own.
To get back to my introduction to this post, there’s sometimes a pattern in the science media of naive beliefs about what mathematical modeling can do. We’ve seen it in the uncritical celebration by Malcolm Gladwell of the uncalibrated claims by John Gottman that he could use mathematical models to predict divorces. We even see it in some of the media treatment of Nate Silver, when people act as if he has some secret formula rather than (as Nate himself insists) simply using good data, sensible models, and hard work. And a few years earlier, the celebration of Steve Levitt as a guy who’s statistical sumo wrestling skills could be used to catch terrorists. Again, let me be clear: Nate Silver and Steve Levitt do excellent work; I’m not criticizing them, rather I’m criticizing the attitude that they’re doing something magic.