Back in 2007, Tim Keck, this paper's publisher, handed me this NYT article, "From Ants to People, an Instinct to Swarm," by Carl Zimmer, a popular science writer. The subject of the piece was a kind of social behavior, swarming, that ants and certain birds seem to do better than humans. Here is the nut:

Americans spend a 3.7 billion hours a year in congested traffic. But you will never see ants stuck in gridlock.

Army ants, which Dr. Couzin has spent much time observing in Panama, are particularly good at moving in swarms. If they have to travel over a depression in the ground, they erect bridges so that they can proceed as quickly as possible.

“They build the bridges with their living bodies,” said Dr. Couzin, a mathematical biologist at Princeton University and the University of Oxford. “They build them up if they’re required, and they dissolve if they’re not being used.”

The reason may be that the ants have had a lot more time to adapt to living in big groups. “We haven’t evolved in the societies we currently live in,” Dr. Couzin said.

There was something that bugged me about this article, something that just did not seem right, something that went/bent a little like this: Is "Instinct to Swarm" saying that traffic jams are just natural? If so, is it then really saying (at a deeper and darker level) that traffic jams are not political? And if so, we had to see the core politics of this line of thinking: Traffic jams have nothing to do with the fact that there are too many cars on the road but with the fact that humans lack the necessary instinct to master the form of social behavior that's proper to traffic harmony...

Six years after reading Zimmer's troubling article, I read this passage in Martin A. Nowak's 2011 book SuperCooperators: Altruism, Evolution, and Why We Need Each Other to Succeed:
Put 400 chimpanzees in economy class on a seven-hour flight, and they would stumble off the plane with bitten ears, missing fur and bleeding limbs. Yet millions of us tolerate being crammed together in this way so we can roam about the planet.
What first surprised me about this chimps on a plane business is that it was identical to what the sociobiologist Sarah Hrdy famously wrote in the opening chapter of her 2009 book Mothers and Others, and yet there's no such attribution in SuperCooperators. But that is another matter for another time. And besides, SuperCooperators is a good read (it provided me with a theory for forgiveness), and Nowak, who is a mathematician, has done great and very controversial work with the biologist E.O. Wilson on group selection theory.

But here is my point. On my way to work a few days a go, I saw the Link train orderly enter the Columbia Street Station, open its doors quickly, release and accept passengers neatly, and depart smoothly. At that moment I recalled the chimps on the plane thing I had just read in SuperCooperators, and also saw the traffic on MLK, and finally there was the answer to Zimmer's swarming: Humans may not be great with traffic, but we are good at sharing small and crammed spaces. Because each of us can easily tolerate others, strangers, crying babies, we can sit peacefully in a container and move together in a mode that's even more efficient than swarming. Swarming is expensive. Each participant in a swarm is burning its own energy. When humans share a space, we can move without each participant burning so much energy. Cars are then doubly inefficient: they are run by an animal that's not really made for swarming, and they burn a lot of energy in the process.