Also called “social lubricant”, laughter does not only make one feel better but also more cooperative and altruistic toward strangers.

Previous studies showed that laughter promoted group cohesiveness. In the new study, researchers decided to test if this sense of closeness would promote altruistic behavior.

The researchers played either a funny or a serious video to study participants and then let them play a game with strangers to see how laughter affected the balance between group interest and self-interest during the game-play.

All of the participants were given small sum of money they were supposed to invest in either a private fund or a group fund. If they decided to invest their money in the private funds they would get all the money back but if they invested in the group fund, they would have to split evenly among group members no matter how much each person put in.

The study showed that laughter increased their sense of altruism and made strangers invest in the group funds. These results could have a large impact on the way charities or organizations could increase the levels of received donations.

It is thought that it was laughter that promoted group bonding and enabled our early ancestors to work together to cope with a hostile environment.