Shouting a four-letter word when you stub your toe or hammer your thumb may ease the pain. In a British study, researchers had volunteers immerse their hands in ice water and repeatedly shout either a curse word of their choice or a neutral word like table. Those who cursed withstood the pain longer and reported that it hurt less. The reason for the difference may be the fight-or-flight response. Curse words raise your heart rate and prepare you emotionally for battle. In previous studies, aggression and pain tolerance have been linked.