Wednesday, September 7, 2011

Save 1 or 5? It IS a Difficult Question

People make decisions every day.  Most decisions are made without really thinking.  But what happens to the brain when it is confronted with decisions that are not made on a day to day basis, or decisions that test morals?  Joshua D. Greene, along with his colleagues, asked this very question and I was extremely intrigued by their findings. 
Greene asked three types of questions: moral personal, moral impersonal and non moral.  An example of moral personal was “You are standing next to a large stranger on a footbridge that spans the tracks, in between the oncoming trolley and five people. In this scenario, the only way to save the five people is to push this stranger off the bridge, onto the tracks below. He will die if you do this, but his body will stop the trolley from reaching the others. Ought you to save the five others by pushing this stranger to his death?”  Greene then posed a similar question he referred to as moral impersonal: “A runaway trolley is headed for five people who will be killed if it proceeds on its present course. The only way to save them is to hit a switch that will turn the trolley onto an alternate set of tracks where it will kill one person instead of five. Ought you to turn the trolley in order to save five people at the expense of one?” Third he asked a non-moral question like “should you take the bus or train given certain time restraints?”
In the study, Greene performed two experiments.  The experiments dealt with brain activity in the areas associated with emotion, and the areas associated with memory.  In both experiments, the brain changes when given a moral-personal situation were significantly different in every section of the brain than when given a moral impersonal, or non-moral question.  Besides the medial frontal gyrus and posterior cingulated gyrus, the brain behaved quite similar in moral impersonal and non-moral questions. 
It is interesting that even though both decisions involve deciding whether one person should live or five people should live, people struggle with making the decision about the footbridge.  According to the study, most people have no problem flipping the switch to save five from the trolley, but when it comes to actually pushing a person, most people will not do it, even though it would save five.  I myself would have a much more difficult time pushing someone to their death in order to save five people, than just flipping a switch and being completely disconnected from the individual who would ultimately die.  By actually pushing someone, it would become more personal and seem more like murder, even though by not pushing the individual five others would die.  The emotional connection outways what would seem like a simple decision; save one or five?


  1. You provided (a link to) the original document. Well done. Not everyone in the class has adopted this excellent habit yet :-(

  2. I love this puzzle. It makes me try to think around corners to get around anybody being killed.

    The best one I can come up with is: Why not throw myself in front of the trolley to try and stop it. Maybe I will be the right size to stop it. That way, I am not responsible for any deaths except my own, which I freely gave, and I win martyr points, too!

  3. I've had the same problem in an ethics course and there was a huge difference between the amount of people willing to switch tracks and those willing give someone a push. We have talked about why that was and it was that pushing someone felt like you yourself were actually murdering someone, while flipping a switch did not. This experiment answers why they feel so different.

    the usual answer to that is that you yourself can't be the sacrifice because you wouldn't be heavy enough to stop it or some other excuse. But you do bring up the issue of consent. Would it be just to push the person only when that person has given his/her consent, or would it also be just without consent, given that you're saving more lives in the end. This also usually gets axed by saying there is no time for questions putting you back at square one.

    Under the condition that I would know for sure that killing the one person would save the 5 others and that there was no way around it, I would kill the one, however in real life this is never the case.

    If the situation is really so split second that the only solution would be to push a person, I wouldn't have the time neccecary or clarity of mind to assess the situation to the extent neccecary to get me to consider killing the person in the first place. If under those time restraints you do come to that solution, then under similar circustances where there were alternatives you would miss those and sacrifice a human life for nothing.

  4. These questions aren't quite as hypothetical as everyone thinks. Every day, many people are faced with a bitch of a dramatic dilemma. Let my family starve, or commit armed robbery? Marry a total jerk because he has promised to pay for my child's vital surgery? I think that the ethical scientists need to emerge from their ivory towers for a while and look for real world questions that have real world significance.

  5. A pilot locally had to make a similar choice during a crash at an air show on Friday. "Some onlookers said Leeward had done what he could to avoid people on the ground.
    'If he wouldn't have pulled up, he would have taken out the entire bleacher section,' said Tim Linville, 48, of Reno, who watched the race with his two daughters.
    'The way I see it, if he did do something about this, he saved hundreds if not thousands of lives because he was able to veer that plane back toward the tarmac,' said Johnny Norman, who was at the show." - from this article:

  6. push!
    what if an airplane is heading across the atlantic towards NYC. radio silence. ignoring flight protocols. do you scramble a fighter and shoot it down before it reaches land? the people who make those decisions would shoot it down. you gotta push!

  7. @rescogitans:
    That is a completely different problem.
    First off there are no certain casualties in your problem. It might just be a normal plane and so nobody needs to die.
    Secondly it involves chance while the original problem involved certainty. 5 people dead or 1 dead by your action. Your problem has the chance of a plane crash and its potential victems vs the chance of it being a normal plane and the deaths of the people caused by shooting it down.
    Your problem is kill 1 do nothing and or hope for 0 deaths but if you're wrong you get 6.

    Depending on the odds it can indeed be safer to shoot (in you're specific problem that would be the case), but it is no longer fundamentally the option that saves the most lives.

  8. @sharkjack
    I think the element of chance is more typical of actual moral dilemmas, and much more difficult to deal with. Let's say instead of 5 people definitely dying by the train, they each have a 50% chance of surviving. And let's say by pushing the fat man you have a 90% chance of stopping the train. But of course you don't know the probabilities exactly, and you have to basically just guess how likely it is that they will survive. That's a real moral dilemma.

    Or say you and your family are being robbed at gunpoint, and you suspect the gunman plans to kill you all to eliminate witnesses. Should you take your chances at trying to disarm him, knowing that failure will result in certain death for your whole family? How would you go about assessing the odds if suddenly forced into that situation. Here, there isn't any obvious rule to follow like "1 dead person is better than 5."

  9. @Robert: Yeah, normal everyday moral dilemmas almost always contain chance in some form or another and like you mentioned in your first dilemma, you don't even know the probabilities themselves. People can survive some insane stuff, but they can also easily be killed by some minor things. In your example I would not push the man, because killing someone to somewhat increase unclear chances of others is a completely different dilemma from the one in the original post.

    By the way the rule is not obvious. Depending on the ethical theory from which the question is approached, taking the action of killing someone might be more immoral than letting a larger number of people die.

    I don't know what I would do during the situation you describe in the last part of your post. I'm not particularly brave but you can't really predict your own behavior under such stress. From my current perspective (comfortably sitting in my chair) I would say that letting the robber do his thing would be the safest bet, as homocide would both carry a heavier punishment and get more attention from the cops, while he could just let us live and be on his way.
    This isn't actually a moral dilemma. In a moral dilemma the problem is that different moral values clash. In this example there is no clash of values. What you want is clear, namely take the action that has the highest chance of getting your family through the robbery safely. The only problem is determining these chances.
    In the original post, the value of the highest amount of human lives clash with the immorality of taking a life.

    My main point against rescogitans was that he used a terrible analogy to back up his choice in the original dilemma, not that the analogy he used was itself less of a moral dilemma.

  10. I don't think that moral questions like this need to be more lifelike to be valid. What you're searching for is a clear pattern, and the simpler the question the clearer the answer. The point is that the majority of people made the same response to that unrealistic question. The interesting question now is WHAT underlying idea unifies our responses? The hypothetical situation may not be realistic but the pattern of moral attitudes revealed in the responses is real.