David DeSteno, director of the social emotions lab at Northeastern University, demonstrates one of his experiments designed to isolate and quantify feelings of jealousy in a laboratory setting.

DeSteno sets up a budding love triangle between three human subjects — one is unwitting, the other two are in on it. The unaware participant is then rejected by the others. Things get really interesting when DeSteno offers the jilted party a chance to exact revenge.

The experiment reveals surprising things about what makes us jealous and why. It also answers the question of who gets more jealous: men or women?