The problem with The Trolley Problem

Opened the last Atlantic and finally read the piece I’d been putting off for some time–Robert Wright’s essay on innate morality (“Why We Fight and Can We Stop” in the print version). I put it off because I often find Wright to be . . .umm, rather credulous, I guess is the phrase I want. He seems to believe strongly that information about the origins of a human trait is always immediately useful in guiding us as to how to deal with that trait. I think that’s a hopelessly naive attitude, so I often find Wright’s work to be more than a little patience trying. On the other hand, he usually deals with interesting topics and its often pretty productive in making me try to figure out why I think Wright (or his subjects) have got something wrong.

For instance in this piece Wright prominent features the work of Joshua Greene, who has helped make the Trolley Problem–an ethical thought experiment–famous. Here it is as conveyed by wikipedia:

There is a runaway trolley barrelling down the railway tracks. Ahead, on the tracks, there are five people tied up and unable to move. The trolley is headed straight for them. You are standing some distance off in the train yard, next to a lever. If you pull this lever, the trolley will switch to a different set of tracks. Unfortunately, you notice that there is one person on the side track. You have two options: (1) Do nothing, and the trolley kills the five people on the main track. (2) Pull the lever, diverting the trolley onto the side track where it will kill one person. Which is the correct choice?

There is a variation:

As before, a trolley is hurtling down a track towards five people. You are on a bridge under which it will pass, and you can stop it by dropping a heavy weight in front of it. As it happens, there is a very fat man next to you – your only way to stop the trolley is to push him over the bridge and onto the track, killing him to save five. Should you proceed?

Many people opt to pull the lever but not push the fat man, in spite of the fact that the end results are the same. Some use this result to argue that human moral reasoning is essentially irrational, or that our moral reasoning has less to do with outcomes than it has to do with keeping ourselves above moral reproach:

. . . people who obey their moral intuitions and refrain from pushing the man to his death are just choosing to cause five deaths they won’t be blamed for rather than one death they would be blamed for. Not a profile in moral courage! 

But there is a big problem with this sort of thought experiment–they depend on the subject feeling a sense of certainty about outcomes (the five people in the car are definitely heading to certain death; the fat man’s fall will definitely stop the train; the diverted train will definitely hit the one person on the track you divert to). Our life experience–the experience our brains have evolved to cope with–is all abut dealing with unexpected contingencies. We very seldom face situations where we know for certain what the consequences of our actions will be, and our natural suspicion when faced with the fat man situation is not that we’ll have one death blamed on us–it’s that we’ll have six. That’s how we think, even when told not to. We are beings who have evolved and grown up to deal with unexpected contingencies–we actually come to expect them in a way, and we tend to act modestly as a result. That’s what the Trolley problem really points out. That’s why we like Captain Kirk’s solution to the Kobayashi Maru dilemma (he cheated), because in life there are lots more contingencies, uncertainties and opportunities than there are in tests and experiments (experiments being designed to absolutely minimize all of these). By attempting to test real-world judgements with a controlled experiment, all the Trolley Problem does is reiterate the difference between experience and experiment.