The classic trolley problem, developed by Philippa Foot in 1967, explores of the moral dilemma that action vs. inaction can pose. In the basic scenario, you see a runaway trolley barreling down a track toward five workers. The only way to avoid those workers’ certain deaths is by pulling a lever to switch the trolley to an alternate track. The problem is that there is one worker on that other track who will be killed if you do it.
Do you pull the lever?
Most people say, “yes, I would pull the lever.” It seems like a simple problem: one person is getting run over, instead of five. A good utilitarian always pulls the lever and about 80% to 90% of people behave like good utilitarians here.
Yet, you can make small changes to the hypothetical that result in big changes to how likely people are to sacrifice one life to save five.