Psychologist Brad Bushman discovered this after insulting volunteers until he was pretty sure they were ready to slam his balls in a car door. Then he separated the participants into three groups: The first group was given a punching bag and told to wail on it while thinking about his own stupid science face. The second was also given a punching bag, but were told to focus instead on getting fit. The third was given jack and told to suck it up.
"If you absolutely need to punch something, you've got a skull."
When asked later to describe how angry they still were, the first group reported that their cathartic punching session had little or no effect on their mood. The second group reported some improvement. But the best results in terms of getting past their anger came from the third group, who did nothing whatsoever.
That may put a spanner in the burgeoning field of "punch therapy," but surely there's a lot to be said for talking it through with someone rather than lying in bed and letting it ferment until it explodes like bathtub moonshine. But in another study, Jennifer Parlamis of University of San Francisco pissed off another test group and then had them write a letter about their feelings to either a mediator, a therapist, a friend, the offending party, or nobody. Again, the group who experienced the biggest reduction in negativity was the group who didn't write a letter. Maybe don't whip out this little theory the next time somebody starts road raging on you, though. Telling an angry person that the best way to deal with it is to just shut the fuck up about it would probably only make the situation worse.