Take 59 Australian students, and split them into three groups. Get two groups to write about something they did that they feel guilty about.
Then get one of those groups to stick their arms into iced water – if you’ve ever tried to do that for a long time, it hurts! The other group gets nice warm water. The third group writes about just some everyday interaction, but then they get the ice bath too.
Two recent studies have shown that people who feel guilty feel less guilty after they’ve been subjected to pain.