SSS 2008-12-17（在线收听）

This is Scientific American's 60-Second Science. I'm Karen Hopkin. This will just take a minute.

When it comes to pain, it’s the thought that counts. Because pain hurts more when it’s inflicted on purpose. Or so say researchers from Harvard University in the December issue of Psychological Science.

Forty-three people were paired off with a partner for what they were told would be a test of psychological perception. Then they were hooked up to some electrodes, and given a quick zap. Sometimes the shock was “intentional.” So, the partner would call for a shock to be administered, and zzzt it came. But sometimes the shock was unintentional. That is, the partner called for the subject to hear a pleasant tone, but those zap-happy researchers hit the shock button instead.

They then asked the subjects to rate the pain. The results? On a scale of one to seven, with seven being “extremely uncomfortable,” the shocks that were done on purpose rated a respectable 3.6. But the same exact shock when given by accident only rated a 3.

That emotional response to pain makes evolutionary sense, the researchers say. Because an ouch that’s just an accident is probably one-time thing. Whereas someone who wants to do you harm will probably do it again. In which case it may be a good idea to pull off your electrodes and just go home.

Thanks for the minute for Scientific American's 60-Second Science. I'm Karen Hopkin.