SSS 2009-03-05（在线收听）

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

“Well, that just leaves a bad taste in my mouth.”

It’s a phrase you’ve likely used at one time or other. And chances are you were talking about something you found morally offputting, as opposed to, say, curdled milk.

Scientists from the University of Toronto say that our reactions to immorality and sour milk may be more similar than we think, because both elicit the same sort of grimace of disgust.

The scientists recorded the facial expressions of subjects who were asked to sip some awful-tasting beverages; brews that were really bitter, salty, or sour. And the drinkers pulled some pretty awful faces, with noses wrinkling and lips curling in disgust. They also made very similar faces when they were shown some yucky photos: pictures of dog poop or dirty toilets.

Finally, the subjects played a game in which they were treated unfairly: say, given only one dollar while a partner got nine dollars. In addition to looking peeved, they also trotted out those sneers of disgust. Findings published in the February 27th issue of Science.

The scientists conclude that our aversion to bad behavior and to bad food may have evolved from a primitive defense mechanism that nowadays protects us from both insult and injury.

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