The "trolley problem" is a classic dilemma used to illustrate how human emotions can change ethical decisions. In the first version, a trolley is headed towards 5 people tied to the tracks. You are given an option to throw the track switch, but it will kill one person tied to the alternate track. Most people choose to throw the switch, even though they're actively causing someone's death. Then they're asked whether they would throw a fat man in front of the trolley to stop it. Even though it's the same, many people balk at this option, showing how our human, emotional biases affect decisions. BUT NOT THIS KID.

Sources: h/t ProfessorSoandSo