Variations taken from this comment on Reddit. I’d like to give my amateurish comments on each variation.
Note that in all of these variations, the six people at risk are tied down onto the tracks. This is different from the example when it’s described that the six people are on the tracks of their own free will (perhaps workers, perhaps just taking a walk on the tracks) but simply cannot hear the trolley running towards them. Thus, we can assume that the six people have been tied to the tracks against their will.
Most people would say not to push the fat person over the bridge to stop the trolley, betraying some sort of morality that is not strictly utilitarian. In this variation, I think reciprocity (a very common theme in morality, I’m sure) gets highlighted. Although the six people may be tied down against their will, the fact here is that you and the fat person, observing from the bridge, have more in common than with any of the people being tied down. You would not want the fat person to be thinking of pushing you down the bridge (next time the situation occurs, perhaps the trolley is much smaller and lighter and so your body on the tracks would suffice, even if for this time, only the fat person’s body would be big enough). Thus, you don’t push the fat person off because you don’t want to be pushed off next time. However, I do think the assumption that “you and the fat person, observing from the bridge, have more in common than with any of the people being tied down” is needed. If this wasn’t the case, it’s less clear. In the extreme, say this is a war situation and you are in you base. The six people tied down are your fellow soldiers (perhaps enemy spies came in the night and tied them down), and the fat man is an enemy prisoner-of-war (imprisoned in the base, perhaps under your guard, perhaps you captured him) that just happens to be beside you at this moment. If you judge that you have more in common with the six tied down, pushing down the fat prisoner-of-war may be more likely since though you may be committing a war crime, you are saving six of your soldiers. The theme is again reciprocity – you have more in common with your fighting mates than with an enemy. If you’re in trouble next time, you’d want your fellow soldiers to sacrifice an enemy if it’ll save you.
Another aspect (still related to reciprocity) is that of shame or later social consequences. If the situation happened in regular life (not war), pushing the fat man off the bridge would likely mean having to try to proclaim your innocence in trial or something. I think there’s an assumption that it’s more likely that you’ll be tried for murder for pushing the fat man off than you’ll be tried for being a bad Samaritan for not doing anything on the bridge. And even if you win your trial in the former case, no one would want to walk on a bridge with you ever again. But if you were a king, or a god, or playing a computer game, and this situation happened to you, I think pushing the fat person off the bridge becomes more likely. Or even simply if you’re a farmer and the fat person and the six people tied down instead are all livestock, like cattle or pigs. So, in the end, it’s reciprocity, again. Shame and social consequences occur because of reciprocity – people see that you won’t reciprocate, so they shame, ostracize, harass, or physically harm you. But if you’re removed from that expectation and pressure of reciprocity, it is much less repugnant to be strictly utilitarian. It seems that we’re first reciprocal, then utilitarian.
A different theme rears its head in this case, which is self-preservation. If we allow the desire for self-preservation and the subsequent actions that that leads to (and it is likely that in a society where we reciprocate, if I want to preserve myself, I allow others to preserve themselves as long as it doesn’t endanger my self-preservation), then we allow the people that have been tied down to want the trolley to run over the people on the other side if it will save them. But we can’t expect society to care for every person’s preservation – at some point, we leave people to self-preserve themselves. We don’t hire security guards to guard every single street, intersection, door, hallway, and window in our society, or produce the best bear suit armors for everyone to wear. Instead, we just hire enough police, and have enough laws regarding helmets for motorcycle riders, seat belts regarding car passengers, and airbags regarding car makers. We don’t know what caused the six to get tied to the tracks. Maybe it was purely chance – an act of god (the six truly don’t deserve it). Or maybe it’s wartime and these are enemy spies or traitors from your side that have been captured are supposed to be humanely executed tomorrow but a renegade official particularly angry at them has decided to execute them more gruesomely a day before in secret. In any case, if it isn’t an act of god, something caused them to be there. Maybe they weren’t careful enough. Maybe they couldn’t buy bear suits for their protection in time. Anything could be the reason, but the people on the bridge were somehow able to self-preserve enough to not be tied down and the people tied down were not able to self-preserve enough to avoid being in their situation. At some point, we ask people to self-preserve themselves. A person tied to the tracks is allowed to wish for his or her self-preservation over others, and the people on the bridge are allowed to not have to risk their own self-preservation just because they’re on a bridge seeing the trolley bear down on those six.
If this is implying that the moral duty might be to pull the lever, it seems to be implying that if you are selfless enough, then the moral duty is the utilitarian answer of saving five people instead of saving one person (despite it being called the “Kantian” variation). If we allow people to desire self-preservation, we allow the one person to let the trolley kill the other five people. If not, it seems that (at least the author of the title of the graphic is saying that) we default to utilitarianism (a sort of “Kantian utilitarianism? I have no idea). So, first comes self-preservation, then comes reciprocity. Then comes “default” utilitarianism.
If self-preservation comes first, then it is more likely that we’ll be one of the five tied down than the one tied down, so we’d pick for the trolley to run over the one person. While we’re picking the same choice as the utilitarian choice, that’s not our reasoning – our reasoning is purely for self-preservation.
I think reciprocity is the name of the game here (and note how self-preservation is not, since if we’re standing at the lever, our self-preservation is not at danger). If we feel something in common with the six people tied down, reciprocity makes us save them. If we don’t feel the expectations and pressures of reciprocity – if we are a king, god, or we’re playing a computer game, then we may be the hedonist and let the six die for our amusement.
Allowing self-preservation allows us to not pull the lever. If we were kings or gods or playing a computer game, we might command the two to pull the levers so that we get a utilitarian outcome. If both the red-dotted person and black-dotted person were not standing on the tracks, it is possible for both to pull the level for the utilitarian outcome.
My amateurish analysis is that it’s likely that most people choose their actions according to self-preservation, some form of reciprocity (depending on who you feel in common with – who are your allies and who are not), and utilitarianism in that order.