The exact mechanism and reasons of why people yawn in response to others is still not clearly understood. The 2005 research may point the way to where to look for more clues about this interesting and automatic human behavior.

Other explanations include the idea that yawning may have evolved in early man as a way to signal or set up sleep schedules. A contagious yawn meant that perhaps more than one person was tired and people should sleep accordingly. Since tiredness might indicate a less energetic response to danger, yawning would mean people should find shelter and get out of danger. Those who yawned and paid attention to it may have been selected into the species because they got proper sleep and were more alert to danger.

This does not explain specifically why people find yawing contagious, but it does suggest that there are brain sections responsible for a person’s perception of a yawn. In addition, the response does not begin with the mirror neuron system but instead bypasses it.

Instead, researchers found that seeing someone else yawn seems to render the periamygdala sections of the brain inactive. This is a tiny part of the brain on either side of the head that helps interpret things like facial expressions. If it was working, the conscious response to yawning might be, “Oh, he’s tired.” By temporarily blocking such a reading, however, the response cannot at first be a conscious perception.

When a person witnesses someone else yawning, he or she has a mostly unconscious urge to do the same. People may become conscious of the urge, but scientists suggest the beginning of the yearn to yawn is unconscious. This means that the signal must bypass the mirror neuron system, which is a process that would make this response a conscious and imitative act. Scientists have often, in the past, suggested that the mirror neuron system causes yawning.

Most people, when they see someone else yawn, quickly feel the urge to yawn as well. Between 40 and 60% of people automatically find yawning contagious and yawn themselves. The standard answers from scientists as to why people find yawning contagious used to be that, although it was clearly a real phenomena, there was no obvious reason for it. Research conducted in 2005 by Finnish scientists, however, may point to certain parts of the brain as being responsible.

Tricia has a Literature degree from Sonoma State University and has been a frequent wiseGEEK contributor for many years. She is especially passionate about reading and writing, although her other interests include medicine, art, film, history, politics, ethics, and religion. Tricia lives in Northern California and is currently working on her first novel.

Discussion Comments

anon965301 August 11, 2014 I read so many people's comments about yawning that I yawned eventually.

anon291580 yesterday I had observed more than 100 times when among many persons when I am yawning, one other person is yawning that too without watching me. So what about the other ones sitting around? If it is due to lack of oxygen supply, why didn't it affect others sitting around.

anon234971 yesterday I yawned several times while reading this! So weird!

anon188092 June 20, 2011 It seemed like I was the only one after reading every comment who had no urge to yawn just because i was reading about it. Even after being tired and up all night I have not yawned once reading the word and the psychological thinking behind it about 500 times. If I ever get the urge to yawn seeing someone else yawning I usually block out the urge, because being consciously aware that it is just due to so called contagiousness of yawning. I would rather not have primitive mirrored responses rule my behavior.

anon165743 April 6, 2011 Rather than a lack of oxygen, I think you yawn because of a build up of carbon dioxide. It is well known that levels of carbon dioxide in the blood are much stronger regulators of breathing than levels of oxygen. A big expiration/breathe out clears away most of the air in your lungs thereby expelling the carbon dioxide (waste product of cellular metabolism) and increasing the levels of oxygen (like food for the cells, together with glucose). As for being contagious who knows, but I've been yawning all the way through reading the posts!

anon165250 April 4, 2011 i yawned three or four times while reading it!

anon146400 January 26, 2011 Of course yawning is due to lack of oxygen, and i have noticed this. According my studies, i observed this from a class of people (which many of you must have noticed), when one yawns the other does not yawn if he doesn't notice the one who yawned. When"A" yawned on looking and noticing that "C" yawned, but "B" didn't notice them yawning and was continuing with talks with "D". Also, sometimes without looking at someone yawning, we yawn. This may be due to the reason that there is an insufficient supply of oxygen, which makes people keep yawning even without looking at each other.

anon145011 January 21, 2011 I actually made it through without yawning but I wonder if it was somehow an unconscious decision to just see if it was possible.

anon140768 January 8, 2011 even reading about yawning makes me yawn.

anon138857 January 2, 2011 This is a question I've wanted an answer to for years. i never thought to look it up online. lol. anyhow, i read another article before this one and in the article it said that you would probably yawn by reading it. literally two minutes later i yawned.

anon137434 December 27, 2010 ha! i yawned twice!

anon127598 1 hours ago wow. i actually yawned once while reading this, it must be some kind of thought process that we haven't evolved out of yet.

anon107839 August 31, 2010 This made me yawn! Just by reading yawn several times it made me yawn! --Shriya

anon99616 July 27, 2010 I think yawning is beyond a simple imitated action but an act to keep a social group alert. Have you felt that cold sensation in your brain when you yawn!? I live in Canada and when I yawn (specially a big one) I immediately feel the temperature difference in my head and this gives me at least couple minutes of alert state of mind. It makes sense to say that this could be a habit inherited from our previous stages of evolution. If you are in the wild and falling in to a sleepy state you are most likely to be not as reactive and more open to danger and if one member yawns, this would be spread through the herd to keep all members alert. I noticed this at the toronto zoo when I yawned in front of a chimp and he yawned right after me.

anon94606 July 9, 2010 I'll tell you why i think yawning is contagious and this is because when you witness a person yawning the first thing you think is he's yawning or you may think just the word yawn, so by you thinking the word yawn the word yawn is now in your brain. So your brain then gives the order to yawn and so you do and so on and so on for everyone who is in the room. To prove me right, just think the word yawn. Don't say it out loud, but just think it in your head. I'll bet within one minute, you'll yawn!

anon92227 June 26, 2010 I'm really tired right now, so I couldn't make it through this entire article. However I yawned once during the parts I did read, and have been yawning off the flippin' walls reading all of your comments. Something strange is going on here. Yawning is a mystery so trivial and deep at the same time, that it seems like the mystery is never truly solved. Maybe we will have a definitive answer some day, people!

anon89013 June 8, 2010 I felt like yawning while reading the article, yawned once while reading comments and yawned while typing. Oh, and I once yawned after seeing a cartoon dog yawn on TV. I've been dying to know the answer to this question for years and I still don't know the answer.

anon86453 May 25, 2010 i just yawned three times while just reading the word yawn and i just did it again when i typed yawned and yawn and now im yawning again.

moronicpest May 25, 2010 Contagious yawning works on me even when watching someone yawn on a webcam without their mic being on, so it doesn't rely on the sound of yawning at all. The sight of a yawn is enough. I think the contagiousness is related to some kind of unconscious programmed need we have to follow the lead of others as some sort of learned socializing survival skill, the yawner being the leader. When we yawn following the lead yawner, we may be unconsciously saying we want to be in the lead yawners social circle on some level. I find I'm more likely to yawn unconsciously if I'm watching a face I find attractive, than one I find unattractive. Smiling can be contagious in a similar but not quite the same way.

anon83603 May 11, 2010 Never yawned once during this thing. I always have fun making many child go to bed, because I yawn in front of them, they get the contagious yawn, start rebounding yawns off each other, and realize they're tired, and go to bed. it's also funny to watch my cat yawn because then i need to yawn!

anon79657 April 23, 2010 People yawn because of lack of oxygen. Maybe I yawn at the same time as someone else because seeing another person yawning may trigger a sort of panic mode in my brain, something like a signal saying "there isn't much air here, and you're probably not breathing enough" even if there's plenty of air, it could be because people don't breathe deeply enough. I don't know. Thinking out loud. Didn't yawn once, because I didn't think about yawning.

anon74450 April 2, 2010 this was so bizarre. i yawned in the beginning a lot. then i read the part where the person said that you just have to laugh and i laughed really loud. what strange thing this is to think of. life is peculiar.

anon74354 April 1, 2010 Yes, very true. I've never thought of yawning that way before! I am going to try to make my dog yawn now!

anon73985 March 30, 2010 I think yawning is contagious because when someone sees/hears someone yawning it makes them think about yawning and that makes them yawn. But, sometimes people see/hear someone yawning but don't yawn, and I think that's because it depends what state of mind you're in. Or, if a person hears someone yawning, it might seem like a relaxing sound, so it makes that person tired, therefore making them yawn. I doubt my theories are correct, but it was worth a try.

anon72992 March 25, 2010 I think yawning might be contagious as a good laughing sound is, especially when people are relaxed, open-minded and in empathetic mood. By the way, while reading the research findings, I didn't yawn. I was rather curious and keen than empathetic toward the writer. However, once I started reading people's comments, I also started yawning. I found myself being empathetic.

anon68322 March 2, 2010 i didn't yawn once while reading this.

anon66371 February 19, 2010 So is yawning contagious?

anon62225 January 25, 2010 I yawned only once while reading this, and am yawning as I type this. It can't be just from visually seeing someone yawn. Just talking about it, or the thought makes you have the urge to yawn.

anon60433 January 13, 2010 i yawned 12 times while reading this!

anon58952 January 5, 2010 i seriously just yawned twice just from reading these few comments. one of life's mysteries.

anon56011 December 11, 2009 read this without yawning. yawn, yawn!

anon55934 December 10, 2009 While the sound of a yawn may be one trigger, it could not be the only trigger. I too, will yawn if I read it in a book (might have something to do with my mind acting out the words on the page). I also yawn if someone does it over the phone, on TV, etc. I have always wondered why?

anon55369 December 7, 2009 I yawned simply by reading the word yawn frequently. =P

anon53405 November 20, 2009 The most interesting thing about it all, in my opinion, is that many animals share this behavior. I have gotten both of my dogs (both aussies) to yawn countless times by yawning in front of them. It's actually quite fun to do, since sometimes I feel like they don't want to yawn, so they try to look or walk away, but they always succumb eventually. On the other hand, I have not had as much success with my cat, but I haven't tried to get him very much, so I'm not sure if it's possible yet.

anon52083 November 11, 2009 yawning is weird but cool because when you yawn and someone else yawns after you, you can't help but laugh.

anon51249 November 4, 2009 Am just playing an online game and while we were chatting we considered how a yawn was Contagious, As neither of the group can see us yawning, but we can hear each others yawn also caused the rest of the group yawn. Also someone yawned silently and this caused others to yawn. I believe it is triggered by the sound, even though someone yawned silently this would not have stopped the sound of air moving across a microphone as air would still move in /out and that would produce at least some lower sound frequencies which would still be audible.

anon26725 February 18, 2009 contagiousness of yawning causes you to wonder if that strength differs if that person is of higher/lower status. Is that true?

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