E.J. Masicampo is a psychology professor from Winston-Salem, North Carolina. He has a 2-year-old son, called Nicholas.
This week, Masicampo discussed the trolley problem with his moral psychology class. When he got home, he thought it'd be interesting to see how his son would react to the moral dilemma.
It didn't go great.
No, Nicholas. Please, no.
Since it was uploaded yesterday, the video has been watched over a million times.
Masicampo told BuzzFeed News that the video was originally made for his class, but after he put it on Facebook it gained a huge amount of unexpected attention.
When asked about his son's response to the dilemma, Masicampo said, "In the meantime, my wife and I will continue trying to teach our son that it is wrong to harm others. He's a good kid. But he's 2. So he'll get there."
Rachael Krishna is a reporter for BuzzFeed News and is based in London.