Humans can smell fear - and it's contagious

By Tia Ghose, LiveScience 

Humans can smell fear and disgust, and the emotions are contagious, according to a new study.

The findings, published Nov. 5 in the journal Psychological Science, suggest that humans communicate via smell just like other animals.

"These findings are contrary to the commonly accepted assumption that human communication runs exclusively via language or visual channels," write Gün Semin and colleagues from Utrecht University in the Netherlands.

Most animals communicate using smell, but because humans lack the same odor-sensing organs, scientists thought we had long ago lost our ability to smell fear or other emotions.

To find out, the team collected sweat from under the armpits of 10 men while they watched either frightening scenes from the horror movie "The Shining" or repulsive clips of MTV's "Jackass."

Next, the researchers asked 36 women to take a visual test while they unknowingly inhaled the scent of men's sweat. When women sniffed "fear sweat," they opened their eyes wide in a scared expression, while those smelling sweat from disgusted men scrunched their faces into a repulsed grimace. (The team chose men as the sweat donors and women as the receivers because past research suggests women are more sensitive to men's scent than vice versa.)

The findings suggest that humans can communicate at least some emotions by smell, which could prove useful in crowded places, the authors suggest.

"Our research suggests that emotional chemo-signals can be potential contributors to emotional contagion in situations involving dense crowds," the authors write in the study.

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Discuss this post

Do you think we can smell stupidity?

  • 3 votes
Reply#1 - Wed Nov 7, 2012 3:36 PM EST

Stupid is as stupid smells?

    #1.1 - Wed Nov 7, 2012 5:23 PM EST

    I smell something fishy here.

      #1.2 - Wed Nov 7, 2012 8:28 PM EST

      Have you ever been in a roomful of republicans ?

      It doesn't smell like a roomful of kindergardeners or a roomful of Ministers !

        #1.3 - Wed Nov 7, 2012 10:23 PM EST

        We are past the election. PLEASE drop the politics.

        And of course we can smell emotions. Humans didn't last this long without having other senses than the basic five. If you couldn't sense something behind you about to eat you your species won't live long, and we have many abilities that we are told as children not to use. It's unfortunate that we do that in the US (not all cultures quash the natural sensing abilities their kids have) and many other countries, but hopefully it will become mainstream to use them all.

        • 2 votes
        #1.4 - Thu Nov 8, 2012 8:28 AM EST

        The MythBusters just tested this last week. However, they used both male and female "scared sweat".

        They came to the same conclusion, plausible.

        Good job NBC News, you're reporting the same thing a science TV show already did!

          #1.5 - Thu Nov 8, 2012 11:23 AM EST
          Reply

          I have said for years, I can not reliably tell by expression when someone is in fear - but I can "smell" it. Not like smelling cheese being added to pasta, much more of a sublime yet confident instinct even though I can't describe it.

          • 1 vote
          Reply#2 - Wed Nov 7, 2012 4:14 PM EST

          Yep, that makes sense. You can feel it coming off someone if you let yourself, too. The energy changes...add the smell factor and humans aren't so blind to everything as common "knowledge" says. We can sense things in many ways...your realization that you can smell fear is a good thing and something you can use to stay safe or protect someone else.

          • 1 vote
          #2.1 - Thu Nov 8, 2012 8:32 AM EST

          Yes, there's so much mental processing going on below the cerebral cortex, we're not consciously aware of. A huge amount of sensory input never even reaches the conscious portions, and that's where almost instantaneous analysis of a situation occurs - which we call "instinct" or "gut feeling" or whatever. Pay attention to those feelings; that ability kept all of your ancestors alive long enough to keep your lineage going. Just because we're "civilized" doesn't mean that ability is irrelevant now. Especially young women - DON'T ignore those little red flags, especially for the sake of politeness. If you're with a guy and something seems - or smells - wrong, GET OUT.

            #2.2 - Thu Nov 8, 2012 10:44 AM EST
            Reply

            Not only can we smell it, but try this:

            Eat a steak from a cow that died peacefully, in its sleep. The meat is bland and uninteresting.

            Now eat a steak from a cow that died terrified, slightly tortured - the meat is much sweeter.

            Finally, eat a steak from a cow that is standard-issue farm-processed. The meat is similar to died-in-its-sleep cow.

              Reply#3 - Wed Nov 7, 2012 4:43 PM EST

              That's sick. Why would you want to terrify or torture any animal?

              • 9 votes
              #3.1 - Wed Nov 7, 2012 5:20 PM EST

              For the flavor, of course. Though I don't condone the mistreatment of animals, you can certainly tell the differences in the taste.

                #3.2 - Thu Nov 8, 2012 9:20 AM EST

                I seriously doubt it. And if you've tortured animals to find out, you're a sadistic criminal.

                • 2 votes
                #3.3 - Thu Nov 8, 2012 9:55 AM EST

                howieCA -

                There's a reason you want a clean shot when you're hunting, say, deer. A flood of adrenaline (caused by fear) into the muscles causes lactic acid to build up and changes the flavor of meat. It causes a "gamey" flavor. Whether or not it's "better" tasting is up to the beholder.

                • 2 votes
                #3.4 - Thu Nov 8, 2012 9:56 AM EST

                A-1 Steak Sauce. The humane alternative.

                  #3.5 - Thu Nov 8, 2012 10:50 AM EST

                  There's a reason you want a clean shot when you're hunting, say, deer. A flood of adrenaline (caused by fear) into the muscles causes lactic acid to build up and changes the flavor of meat. It causes a "gamey" flavor. Whether or not it's "better" tasting is up to the beholder.

                  True, but most people say that that flavor is NOT as good. But I think the main reason you want a clean shot when hunting is because you don't want to have to track down a wounded animal for miles, or let one get away wounded. Especially if it's a bear! :-)

                    #3.6 - Thu Nov 8, 2012 11:13 AM EST

                    But then - consider

                    That same deer, farm-raised, grain and DGH-fed, quietly led to the slaughterhouse - the meat will come out with that same, bland, mass-produced taste.

                    Whereas, when hunted, that wild flavor, that gamey-ness, is carried over as Lilac points out. And that will be present regardless of if the kill-shot is clean or not.

                    Yes, we want clean kill shots because we want to eat the animal, not torment it. We don't want to track wounded animals for miles, and we don't want excessive bullet-bits in our meat.

                    ---

                    Howie: No, I've never tortured animals, but have eaten both wild and domestic varieties of a number of critters, and differences in flavors are astonishingly pronounced. Here's a grand example:

                    Less than 14 miles from my house is a bison ranch. They raise, slaughter and sell their own bison. It's good, lean, tender meat. Didn't take long to make me a believer.

                    Then four years ago, I was invited to participate in an actual bison hunt. The meat was SO much better, and so much so I conducted my own culinary experiment - cutting wild and domestic bison steaks in half, preparing both halves the same way and plate for plate and bite for bite the wild bison won out over the domestic.

                    Given that the only real differences here are that one is commercially processed and the other is wild and hunted, I can only conclude the difference in flavor due to the fact that the wild bison was so much more rich and flavorful because the animal was fighting for its life, whereas the domestic bison went out rather unsuspectingly.

                      #3.7 - Thu Nov 8, 2012 12:15 PM EST

                      Here's an even better experiment: Slaughter a domestic bison that's been farm-raised, and take another domestic bison from the same herd, turn it loose, hunt it down THAT DAY and shoot it. If you still taste a difference in the meat, then you'll know for sure that it was indeed the manner of death, and not the animal's life-long diet that made the difference.

                      • 2 votes
                      #3.8 - Thu Nov 8, 2012 1:29 PM EST

                      Given that the only real differences here are that one is commercially processed and the other is wild and hunted, I can only conclude the difference in flavor due to the fact that the wild bison was so much more rich and flavorful because the animal was fighting for its life, whereas the domestic bison went out rather unsuspectingly.

                      Seems pretty obvious to me that it's the "wild" part that is the big difference there. What you feed an animal and how much exercise it gets are the greatest factors in the content (and thus the flavor) of the meat.

                        #3.9 - Thu Nov 8, 2012 1:45 PM EST
                        Reply

                        We need happy contented sweat donors for crowd control. Instead of pepper spray, chilled out happy sweat spray.

                        • 2 votes
                        Reply#4 - Wed Nov 7, 2012 5:20 PM EST

                        Pot smoke works better.

                        • 5 votes
                        #4.1 - Wed Nov 7, 2012 5:22 PM EST

                        Aerosol Valium might work, too.

                        • 2 votes
                        #4.2 - Thu Nov 8, 2012 9:27 AM EST
                        Reply

                        Umm smelling a chemical response to an emotion is not exactly smelling the emotion.

                          Reply#5 - Wed Nov 7, 2012 6:16 PM EST

                          But the net effect is the same. If you smell the chemical(s) released when someone is afraid then you are in effect smelling the smell of fear. Subtle difference perhaps, but the result is the same.

                          • 1 vote
                          #5.1 - Thu Nov 8, 2012 8:34 AM EST
                          Reply

                          I don't see many people going around sniffing armpits, though.

                            Reply#6 - Thu Nov 8, 2012 9:26 AM EST

                            Finally!! A scientific study that backs the reason I could *always* tell when a fight was going to break out at a bar long before it actually happened. Lends some credence to the expression, "there's something in the air".

                            • 1 vote
                            Reply#7 - Thu Nov 8, 2012 9:48 AM EST

                            I wonder if this varies in degree by culture as growing up in America especially has conditioned us to reduce and cover up odors from sweat via shaving armpit hair and excessive use of deodorants and be repulsed by those that don't.

                            I couldn't help notice that while in France more people in a given sample have more natural scents and although culturally conditioned to be turned off by that, I did find the aromas of a couple women in particular to surprisingly be quite stimulating in a positive way on a very subtle almost primal level. The sensory apparatus is there. We've just forgotten or evolved beyond how to use it beyond the subconscious level.

                            • 1 vote
                            Reply#8 - Thu Nov 8, 2012 10:03 AM EST

                            My husband and I have discussed this and posit that deoderant is a cultural or social tool to (essentially) keep the status quo, orderliness, etc. in public places.

                            • 1 vote
                            #8.1 - Thu Nov 8, 2012 10:18 AM EST
                            Reply

                            All the people who are living off the government got scared they might have to work for a living. The fear spread. Obama got reelected. Now the fear is in the working people wondering how to support the ones not working.

                              Reply#9 - Thu Nov 8, 2012 1:45 PM EST

                              dude, the election is over, go crawl back in the cave for 4 years....

                              • 1 vote
                              #9.1 - Thu Nov 8, 2012 2:03 PM EST
                              Reply

                              I went to a Tea Party rally before the election. I smelled stupid people. Lots of stupid people.

                                Reply#10 - Wed Nov 21, 2012 7:04 PM EST
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