Smell of fear

New research suggests that anxiety triggers the release of a scent that causes other humans who smell it to empathize with you. This may have evolved to help speed up spread of fear within a population so groups can get away quickly from dangerous situations. To run the experiment, University of Dusseldorf psychologist Bettina Pause and her colleagues had students undergoing brain scans sniff absorbent pads taken from the armpits of other students just before a final exam and, separately, while they were exercising. Pleasant.

None (of the sniffing students) perceived a difference between the two types of sweat, but the pre-exam sweat had a different effect on brain activity, lighting up areas that process social and emotional signals, as well as several areas thought to be involved in empathy...

A previous experiment found that sweat from skydivers activated anxiety circuits in sniffers' brains.

Fellow students smell your exam fear

• [Avram / Moderator]

  Bemopolis and Troofseeker, after spending some time in a world where everyone with a drivers license is allowed to pilot two tons of flying metal, you will know fear-stink.

• [airshowfan]

  I’m pretty sure that mean-looking dogs (such as boxers, rottweilers, and dobermans) can smell (or otherwise sense) my discomfort around them. Apparently one way to tell whether or not this is all in my head would be to do a chemical analysis of my armpit sweat when I encounter such dogs (versus my armpit sweat when I encounter a golden retriever or west-highland terrier). Now I wanna look into that.

• [TroofSeeker]

  My son has a lot of his buddies come here. There is only one that our dog barks at- the one that is terrified of dogs. He probably works up a ‘fear sweat’ as he approaches our front door.

  Man has known this for thousands of years! Stop wasting time and, like Bemopolis says, get back to work on that flying car!

• [gwax]

  Re: AIRSHOWFAN@6, TROOFSEEKER@7 : I have seen a very similar thing with my dog, though he seems to interpret the scent of fear as a sign that people want to play; mighty bothersome for a 150# dog sometimes.

• [Brett Burton]

  Empathize? Really? Is there another fear chemical that makes humans who smell it gang up on you? I’m pretty sure that’s the one I have. At least when I was in highschool.

• [jackie31337]

  hep cat @2 This I suppose explains roller coasters, slasher movies, and 600 horsepower rusted out camaros as staples of American dating.

  No, that’s because the perception of danger triggers the release of some hormone (I forget which) that has the result of you considering the person you’re with more attractive as a potential mate. Somebody help me out here?

• [Godot]

  I can verify there is a smell of fear.
  A sickening, sour sweat.
  I last produced while learning to drive, my driving instructor was not very nice.

• [hep cat]

  This I suppose explains roller coasters, slasher movies, and 600 horsepower rusted out camaros as staples of American dating.

• [hokano]

  @ Brett Burton:

  “I have isolated the chemical which is emitted by every geek, dork, and four-eyes. I call it poindextrose.” ~ Lisa Simpson, Bye Bye Nerdie

• [Anonymous]

  Ah yes, the ever elusive human pheremone!

• [phisrow]

  What is interesting about this study is that, in something like half the cases, the subject could not consciously detect any odor(in both the control and the anxiety cases).

  The emotional effect occurs whether or not you can consciously detect a scent.

• [spazzm]

  Avram – as opposed to two tons of metal hurtling along at knee height?

  Troofseeker I can attest to the dog thing. If there’s one person in a group that is afraid of/dislikes dogs, you can bet that a dog will bark at him, and only him. This might be due to other cues such as voice pitch, heartbeat or body language, of course, but they do say that dogs can smell fear.

• [Drew from Zhrodague]

  Hm, Humans don’t have a very good sense of smell due to our tiny olfactory bulb.

  http://en.wikipedia.org/wiki/Olfactory_bulb

  In Humans, it is tiny. In animals like rats and dogs, it is a signifigant percentage of the size of their brains. This accounts for them having a long face.

• [mdh]

  The emotional effect occurs whether or not you can consciously detect a scent.

  I want to assume they tried this with banana scented rags as well as unscented rags, both with and without fear smell.

  Also, I can smell a lot of pheremones. There are at least three different ones I can detect – the smell of a skilled liar, a seeking sex partner, and a terrified person.

  I think there may also be one that makes you quit your job and stay up all night tweeting about suing the media.

• [nerdophyle]

  The olfactory sense has long been known to be one of,if not the most prominent modes by which human beings activate unconscious processes [e.g., evoking memories associated with certain scents, or, in this case, feeling empathy in response to (smelling) another person's anxiety]. In addition, pheromones have long been known to unconsciously influence sexual attraction. The findings of this research, therefore, do not seem so outlandish in comparison to said knowledge about the importance of smell to the human animal. Interesting stuff indeed.

• [Takuan]

  we (some) have vomeronasals. And didn’t an additional pair of cranial nerves just get noticed?

• [TroofSeeker]

  Jackie, I remember that- something about how women sniff men to see if they have good, strong immune systems? Something like that.

• [Bemopolis]

  Big duh — It’s called URINE. Look it up in your nerd tomes, super-scientists. Now get back to those flying cars you promised us.

• [Tania]

  While this is cute and funny, I have difficulty understanding why such a mechanism would be necessary, from an evolutionary or even practical standpoint, given that by the time you can smell someone’s fear, you have already seen it all over his or her face and body language, and you have already heard the person yelp in a high piercing monkey-spots-eagle alarm voice “OMFG VELOCIRAPTORS WTF,” which really does the trick much better.

  Also, “lighting up areas of the brain thought to be involved with empathy” does not necessarily mean “increased empathy.” Also, students before a final exam are by-definition in a state of anxiety. Some of them are surely hopped up on stimulants. Some of them feel confident. Some of them are in blind fear. Some of them are half asleep, hoping to wake up in time. Although perhaps being asked to tuck wads of cotton under your arms right before your final exam really does increase anxiety.