A bad taste in the mouth is more than a phrase

The Breaking Science team revealed some new research suggesting 'a bad taste in your mouth' might be more than just metaphor. Here's a transcript:

Chris Smith: Hello, I’m Chris Smith and this is Breaking Science, which is produced in association with the Open University.

First, with news from across the scientific globe it’s time to join our science reporter, Dr Kat Arney. To kick us off, Kat, the headline in Science is quite funny but it only really works with an American accent which is ‘from oral to moral’, scientists are saying that the way we react to things that we find objectionable is all based originally on foods that we don’t like the taste of.

Kat Arney: Yes, we often use the phrase ‘it left a bad taste in my mouth’ to describe an activity or a situation that we find quite unpleasant. But now researchers writing in the journal Science have shown that there may actually be more to this metaphor than meets the eye.

Chris Smith: Pray tell why?

Kat Arney: Well the researchers, led by Hannah Chapman, wondered if there was any kind of link between the facial movements made when we eat disgusting food, you know, that sort of ‘urgh’, and when we see disgusting pictures or when we experience really unpleasant behaviour so they carried out some intriguing experiments using volunteers.

Chris Smith: I thought you were going to say for a moment you’ve been sampling my mother’s cooking. But go on, tell us, what did they do with their volunteers?

Jupiterimages
Close-up of dog taste buds.

Kat Arney: Well to start with the researchers gave the volunteers different drinks, they were either neutral tasting, sweet or bitter, and then they took close up video images of their faces. And in particular they focused on the actions of a group of muscles called the levator labii, and these are the muscles that make us wrinkle up our noses and raise our upper lips when we taste something nasty. Now unsurprisingly they found that the bitter taste caused a big movement of these muscles compared to sweet or neutral tastes.

Chris Smith: Yes, but how does the disgust at things and the behaviour bit of it come into this?

Kat Arney: Well next the scientists showed people pictures of disgusting things, including poo, injuries, insects, things like that, and they compared these with pictures of sad things and then some neutral pictures for contrast, and the team found that only the disgusting pictures led again to the movement of these levator labii muscles, and the stronger the disgust that the person felt the more their muscles moved. So this is quite intriguing, and the team went on to look at situations where people experienced unpleasant or unfair situations. These were met with these same facial movements of disgust, say, seen with a nasty liquid or unpleasant pictures.

Chris Smith: So give us the bottom line, taking a financial analogy then, what does this mean in terms of how this behaviour maps onto what we actually do in real life?

Kat Arney: Well, the researchers think that this means that moral disgust and outrage actually has similar evolutionary roots to physical disgust, and they think that this physical response to something nasty has probably been co-opted during our social evolution to express our disgust at social and moral situations that we don’t like.

Chris Smith: Indeed.

Listen to the whole programme, as broadcast on BBC Radio Five Live February 2009