Joshua Greene gave a very interesting talk at Penn recently. He discussed variants of the trolley problem, neuroscience and moral intuitions.
Trolley problems involve an out-of-control trolley that will kill 5 people who are on the track in its way, unless you do something about it. However, doing something about it will mean killing someone else (not one of the 5 people).
Original problem: Joe can flip a switch which will send the trolley down a different track (which happens to have a person tied to the track). The majority of people surveyed think it’s morally acceptable to flip the switch.
Footbridge version: Joe is on a bridge above the trolley. Joe can stop it by pushing the large man who is in front of him off of the bridge and onto the track. Most people surveyed do not find this morally acceptable.
Pole version: rather than using his hands, Joe can push the man with a pole. Most people find this unacceptable
Remote footbridge version: Joe has a remote control some distance away from the footbridge. It controls a trap door that could drop the man onto the track and stop the trolley. The majority of people find this morally acceptable
Footbridge switch version: This is the same as the remote footbridge version, except the trap door switch is on the bridge (so that Joe is in very close proximity to the trap door). Most people found this morally acceptable.
The contribution of science is not in telling us what the right answer is in each case. The purpose is to isolate factors (such as spatial proximity and physical force). If varying a factor (such as spatial proximity) causes a change in our moral intuitions, then we need to decide if that factor should matter. If we do not think it should matter, then we have evidence that our moral intuitions are untrustworthy.
I was thinking about some new variations of the problem (hey, it’s fun to think about!).
Robot version: there is a robot on the bridge. Joe can use his remote control to make the robot push the man off of the bridge. Morally acceptable? Here Joe is not using physical force, so it is like the trap door. However, I wonder if people picture a robot that looks human (with a head, arms and legs) and associate it too closely with a human pushing the man off of the bridge. Or perhaps it makes people think of evil, mindless robots, which makes them uncomfortable.
Lion version: Joe is a lion trainer and his lion, Whiskers, is on the bridge. If Joe gives the command “Whiskers, PUSH,” Whiskers will push the man off of the bridge. Morally acceptable? Here Joe is not using direct force, but perhaps most people would not like it that he is making the animal do his dirty work.
Name variation: For any of the above problems, would people respond differently if instead of Joe we called him “Damien” or “Jamal”?
Gender variation: Would people have different moral feelings if instead of Joe we talked about Mary? I suspect that people would be even more uncomfortable with a woman making a decision to sacrifice the bridge man.