Sunday, August 02, 2009

Has Anyone Ever Pushed the Fat Man off the Footbridge?

In the famous "trolley problems" (developed by contemporary philosophers such as Phillipa Foot and Judith Jarvis Thompson), a hypothetical observer is faced with several similar-seeming scenarios involving runaway trolleys or the like where there's a choice between letting five people die (if you do not intervene) and doing something that causes one other person to die, in order to save the five. The fun bit is this: Although many of the dilemmas seem similar, our moral intuitons tend to split on them, raising the question of what's driving the intuitions. Although discussion of these sorts of problems began in philosophy, with philosophers relying on their armchair intuitions, psychologists such as Marc Hauser have recently started to look at the psychology of this more systematically.

Two of the most famous scenarios are the "side track" and the "footbridge" scenarios.

In the side track scenario, you see a runaway trolley headed toward five people who will certainly die if you do nothing. You are standing next to a switch that would allow you to divert the trolley to a side track, saving the five people. Unfortunately, there is one person on the side track, who will certainly die if you divert the trolley. Question: Is it morally permissible (or even good) to divert the trolley?

The footbridge scenario is similar except that you're standing on a footbridge above the track. The only way to save the five people is to block the trolley with a sufficiently heavy object. The only sufficiently heavy object you can reach in time is a fat man (alternatively, perhaps more politely, a hiker with a heavy backpack) who is standing next to you. You could push him off the footbridge and the trolley would grind to a halt on his body, killing him but saving the five. You yourself are insufficiently heavy to stop the trolley with your own body. Queston: Is it morally permissible (or even good) to push the fat man?

Most people seem to have the intuition that it is morally permissible to flip the switch to divert the trolley but that it's not morally permissible to push the fat man. Why, exactly, is a very interesting question that I won't go into here. All I want to ask is this: Are there any real life scenarios in which someone has done something like pushing the fat man? Given that there is a non-trivial minority of people who do think it's okay (or even good) to do so, you might think one of them would have been faced with such an opportunity and done the thing. Of course, I'm not asking just about runaway trolleys but about any scenario with a similar structure, in which one kills an innocent person through an act of direct personal violence in order to save several others. I exclude abstract decision making involving administrative balancing the costs of lives against each other in times of war and emergency, such as deciding to reroute life-saving supplies from one place to another or asking one platoon to charge into the fire to save the battalion. What I'm asking about is archetypal violence -- murder, by a civilian in no position of authority, of an innocent bystander -- to save other people's lives.

In other words: Do people ever put their life-counting consequentialism into action? If so, you'd think it would make the news. In the 1980s Bernard Goetz made big headlines when he shot some muggers in a New York subway (and there's even a Wikipedia entry about it). You'd think pushing the fat man would be even bigger news. And although fat-man like scenarios are surely very rare, in this world of billions they must sometimes arise.

(HT: Jeanette Kennett for forcefully posing this issue to me.)


Neil said...

I am more confident in my claim that Jeanette Kennett does not work for Monash University (she's at Macquarie) than I am that I have a case that fits your description. But why not think of Gitmo torture as motivated by consequentialism? Or, for that matter, bombing of civilian areas? There was a case in Germany recently of a police chief convicted of threatening to torture a kidnapper if he did not reveal the location of a child (google it if you're interested: the policeman's name was Wolfgang Daschner).

There is also the case of R v Dudley and Stephens, in which shipwreck survivors drew lots to choose one person to be killed and eaten by the others

Justin said...

The shipwreck case is nice, though it's not strictly altruistic (whether or not that should matter is a further question).

Gitmo cases are more complicated both in that some (many?) of the people involved weren't innocents--many of us think that's no excuse for torture, but it complicates the case nonetheless. Worse, I think is the fact that the benefit was pretty speculative.

No cases of my own, I'm afraid.

Eddy Nahmias said...

I'm not sure if Eric was looking for this, but I'm particularly interested in whether people can come up with real-life (or even believable) cases where (like Fat Man) you have to (a) physically harm a human (satisfying what Greene and others call the "personal contact" condition) and (b) use the human's body itself as a means to prevent harm to others.

I'm interested, because my former student Bradley Thomas and I tried very hard to come up with such a case that is *believable* (unlike the Fat Man case)--of course, real-life cases might not be very believable! We wanted to test to see how much of people's reluctance to pushing Fat Man might be explained not by the factors of personal contact/using as means, but by people's intuition that, despite the stipulations of the case, the action is unlikely to work to save five (unlike the Switch case) and/or the decision-maker in the case is *unjustified* in believing that the action will work (so even if it did work, they shouldn't have done it).

We came up with a case within the trolley set-up but it was still convoluted (we did get some interesting results that completely baffled me). In the process, we came to believe that the human body is just not a very good means to prevent disasters.

Eric Schwitzgebel said...

Thanks for the comments! Neil and Justin: Those are interesting cases, but pretty far from the fat man type of case. Perhaps climbers on Everest cutting the rope as in some ways similar, too. In all those cases there is at least some sort of pact or authority involved rather than two bystanders.

I agree with you Eddy, about the problem coming up with good, believable cases!

Bryce said...


A couple of things...

To begin with, you claim that it's a "non-trivial minority of people who do think that it's ok (or even good)" to push the fat man. But it's not clear that anyone ever says that it's good to do this (at least not in any of the work in moral psych that I've read). Some people obviously say that it's 'ok', that it's 'permissible', and that it's 'acceptable'. There are even some people who will say that it's 'required'. But, to the best of my knowledge, no one has ever asked whether it is good to do this. In fact, to my mind, it's not even clear how many people think that it's *good* to divert the trolley.

I've talked to a substantial number of participants in studies where questions like this are asked; it seems to me that the people who say that one should push the fat man typically appeal to utilitarian moral theory when they justify their response. They say: "well, the utilitarian would say it was ok".

I tend to think that the people who say that it's ok, acceptable, permissible, etc., are offering this response from the perspective of having *internalized a philosophical theory* that licenses this seemingly odd judgment. But my guess is that most of these people wouldn't push the guy if they were in this situation--whatever it is that leads most people to say that this is bad would prevent even these people from acting. (In line with this thought, Hauser and I have a paper that is currently under review where we discuss the following bti of data. We asked people about sacrificing themselves in a trolley-like scenario and found that an even more substantial minority said that they would sacrifice themselves to save the anonymous people down the track. It seems reasonable to suppose that *very few* of these people would be likely to do so; and that where they did, it would be a matter of having internalized some overt theory that glorified altruistic self-sacrifice...but that's another can of worms)

But, if this judgment is driven by an overt appeal to a philosophical theory, then it seems to me that even if there were such a case, the person who acted in this way would feel guilty enough (or would be scared enough of ending up in prison, etc) to keep it as quiet as possible. Having violated the commonly accepted norm against pushing the guy, the person who did this would have to acknowledge that they had done something that most people would think was far from admirable (even if they might eventually brag about it after having consumed a fair number of beers).

Eddy Nahmias said...

Bryce raises interesting points. I wonder if one difference between the Switch and Fat Man cases that may influence the different responses people give is that pushing a person to his death is probably perceived to be illegal, despite the good consequences it may have. In fact, I suspect some prosecutors would charge the "consequentialist good samaritan." It's less clear that Switch involves doing anything illegal (perhaps tampering with private property but not assault or manslaughter).

Of course, it may be that the law is following our moral intuitions here rather than the moral intuitions following the legal issues. But, like the serious difference in believability (and justified belief), this is another issue that is entirely ignored in the discussion of these two bizarre cases.

Eric Schwitzgebel said...

Bryce and Eddy, we have data on this, but I haven't partialed out the "good"s from the "morally neutral"s. I'll look at it tomorrow and get back to you!

Eric Schwitzgebel said...

About 20% say it's morally good to push the person off the footbridge, in data I'm looking at right now, which I collected with Fiery Cushman.

The scale is 7 points, running from "extremely morally good" through "morally neutral" to "extremely morally bad"; so it's not about permissibility, directly.

Eric Schwitzgebel said...

Of course, legality is a complicating issue, as you point out Eddy -- not to mention all the problems inherent in survey data!

Anonymous said...

I heard of an similar philosophy problem where there are a group of refugees hiding in the cellar while the Nazis search and there is a crying baby as part of the group - do you suffocate the baby to save the rest of the group from being discovered? In this case, the murderer is presumably saving himself too.

And I once read a newspaper story about a woman who confessed (in old age) that she accidentally suffocated one of her children while hiding from the Nazis in a similar way. I wish I could find that story again and check the details ... it was probably in the Guardian

Anonymous said...

A couple of things:

Have any of you collected info pertaining to subjects' religious beliefs (or lack thereof)? I wonder about the role that a belief in "divine destiny" might play in the moral calculation.

Bryce: re: those who would self sacrifice in order to save a stranger. here's an interesting case:

I guess its especially interesting to me given the commonly held perception of egocentrism in teenagers.

Eric Schwitzgebel said...

I'd be interested to see that story if you find it, Anon Mon 4:05.

Anon Mon 6:39: Thanks for the link. Neat story! Fiery and I didn't collect reports about religiosity, but some of the other versions of the Moral Sense Test out of the laboratories of Hauser and his collaborators do have a question about religiosity in the pre-test. I can't recall any discussion of the relationship between that, though, and the "fat man"-type scenarios.

Bryce Huebner said...

In the numerous version of moral sense tasks that I've run in collaboration with Hauser, we've rarely found any significant effect of reported religiosity. So far as I can remember, there are two interesting cases where we found an effect. One was in a set of cases where you could use a dead body to stop an ongoing threat (e.g., the oncoming trolley); the other was a case where people were asked whether they would sacrifice their own lives to save unknown others.

We are currently going back through a number of MST experiments and looking to see if religion has any significant guess is that we won't find much of an effect for most scenarios

Eric Schwitzgebel said...

Cool, Bryce, keep me posted!

d said...

thanks eric and bryce..
Bryce, if you recall, what was the effect of reported religiosity in those two cases?

thanks for the nice site eric!