Why is yawning contagious? - Claudia Aguirre
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0:07 - 0:10Oh, excuse me!
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0:10 - 0:11Have you ever yawned
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0:11 - 0:13because somebody else yawned?
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0:13 - 0:15You aren't especially tired,
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0:15 - 0:18yet suddenly your mouth opens wide
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0:18 - 0:22and a big yawn
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0:22 - 0:24comes out.
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0:24 - 0:27This phenomenon is known as contagious yawning.
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0:27 - 0:29And while scientists still don't fully understand
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0:29 - 0:30why it happens,
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0:30 - 0:33there are many hypotheses currently being researched.
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0:33 - 0:35Let's take a look at a few
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0:35 - 0:37of the most prevalent ones,
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0:37 - 0:39beginning with two physiological hypotheses
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0:39 - 0:42before moving to a psychological one.
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0:42 - 0:45Our first physiological hypothesis
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0:45 - 0:46states that contagious yawning
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0:46 - 0:49is triggered by a specific stimulus,
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0:49 - 0:50an initial yawn.
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0:50 - 0:53This is called fixed action pattern.
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0:53 - 0:56Think of fixed action pattern like a reflex.
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0:56 - 0:59Your yawn makes me yawn.
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0:59 - 1:01Similar to a domino effect,
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1:01 - 1:02one person's yawn triggers a yawn
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1:02 - 1:05in a person nearby that has observed the act.
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1:05 - 1:07Once this reflex is triggered,
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1:07 - 1:09it must run its course.
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1:09 - 1:10Have you ever tried to stop a yawn
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1:10 - 1:12once it has begun?
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1:12 - 1:15Basically impossible!
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1:15 - 1:17Another physiological hypothesis
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1:17 - 1:20is known as non-conscious mimicry,
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1:20 - 1:22or the chameleon effect.
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1:22 - 1:25This occurs when you imitate someone's behavior
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1:25 - 1:26without knowing it,
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1:26 - 1:29a subtle and unintentional copycat maneuver.
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1:29 - 1:31People tend to mimic each other's postures.
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1:31 - 1:33If you are seated across from someone
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1:33 - 1:34that has their legs crossed,
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1:34 - 1:37you might cross your own legs.
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1:37 - 1:39This hypothesis suggests
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1:39 - 1:41that we yawn when we see someone else yawn
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1:41 - 1:43because we are unconsciously copying
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1:43 - 1:45his or her behavior.
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1:45 - 1:47Scientists believe that this chameleon effect
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1:47 - 1:50is possible because of a special set of neurons
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1:50 - 1:52known as mirror neurons.
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1:53 - 1:56Mirror neurons are a type of brain cell
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1:56 - 1:58that responds equally when we perform an action
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1:58 - 2:00as when we see someone else
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2:00 - 2:02perform the same action.
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2:02 - 2:03These neurons are important
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2:03 - 2:05for learning and self-awareness.
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2:05 - 2:08For example, watching someone do something physical,
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2:08 - 2:10like knitting
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2:10 - 2:11or putting on lipstick,
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2:11 - 2:15can help you do those same actions more accurately.
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2:15 - 2:17Neuroimaging studies using fMRI,
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2:17 - 2:20functional magnetic resonance imaging,
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2:20 - 2:22shows that when we seem someone yawn
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2:22 - 2:24or even hear their yawn,
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2:24 - 2:26a specific area of the brain
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2:26 - 2:27housing these mirror neurons
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2:27 - 2:29tends to light up,
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2:29 - 2:31which, in turn, causes us to respond
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2:31 - 2:34with the same action: a yawn.
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2:34 - 2:37Our psychological hypothesis also involves
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2:37 - 2:39the work of these mirror neurons.
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2:39 - 2:42We will call it the empathy yawn.
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2:42 - 2:44Empathy is the ability to understand
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2:44 - 2:45what someone else is feeling
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2:45 - 2:47and partake in their emotion,
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2:47 - 2:50a crucial ability for social animals like us.
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2:50 - 2:52Recently, neuroscientists have found
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2:52 - 2:54that a subset of mirror neurons
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2:54 - 2:56allows us to empathize with others' feelings
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2:56 - 2:58at a deeper level.
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2:58 - 2:59Scientists discovered
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2:59 - 3:02this empathetic response to yawning
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3:02 - 3:03while testing the first hypothesis we mentioned,
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3:03 - 3:05fixed action pattern.
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3:05 - 3:07This study was set up to show
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3:07 - 3:09that dogs would enact a yawn reflex
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3:09 - 3:12at the mere sound of a human yawn.
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3:12 - 3:15While their study showed this to be true,
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3:15 - 3:17they found something else interesting.
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3:17 - 3:20Dogs yawned more frequently at familiar yawns,
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3:20 - 3:21such as from their owner's,
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3:21 - 3:24than at unfamiliar yawns from strangers.
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3:24 - 3:25Following this research,
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3:25 - 3:27other studies on humans and primates
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3:27 - 3:29have also shown that contagious yawning
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3:29 - 3:33occurs more frequently among friends than strangers.
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3:33 - 3:36In fact, contagious yawning starts occurring
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3:36 - 3:39when we are about four or five years old,
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3:39 - 3:39at the point when children
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3:39 - 3:43develop the ability to identify others' emotions properly.
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3:43 - 3:46Still, while newer scientific studies aim
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3:46 - 3:47to prove that contagious yawning
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3:47 - 3:49is based on this capacity for empathy,
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3:49 - 3:51more research is needed
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3:51 - 3:53to shed light on what exactly is going on.
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3:53 - 3:55It's possible that the answer lies
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3:55 - 3:57in another hypothesis all together.
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3:57 - 3:59The next time you get caught in a yawn,
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3:59 - 4:01take a second to think about what just happened.
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4:03 - 4:05Were you thinking about a yawn?
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4:05 - 4:07Did someone near you yawn?
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4:07 - 4:10Was that person a stranger or someone close?
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4:11 - 4:14And are you yawning right now?
- Title:
- Why is yawning contagious? - Claudia Aguirre
- Speaker:
- Claudia Aguirre
- Description:
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View full lesson: http://ed.ted.com/lessons/why-is-yawning-contagious-claudia-aguirre
*Yaaawwwwwn* Did just reading the word make you feel like yawning yourself? Known as contagious yawning, the reasons behind this phenomenon have been attributed to both the physiological and psychological. It's been observed in children as young as four and even in dogs! Claudia Aguirre visits the many intriguing theories that might explain contagious yawning.
Lesson by Claudia Aguirre, animation by TED-Ed.
- Video Language:
- English
- Team:
- closed TED
- Project:
- TED-Ed
- Duration:
- 04:30
Krystian Aparta edited English subtitles for Why is yawning contagious? | ||
Krystian Aparta commented on English subtitles for Why is yawning contagious? | ||
TED edited English subtitles for Why is yawning contagious? | ||
Jessica Ruby approved English subtitles for Why is yawning contagious? | ||
Jessica Ruby edited English subtitles for Why is yawning contagious? | ||
Jessica Ruby edited English subtitles for Why is yawning contagious? | ||
Andrea McDonough edited English subtitles for Why is yawning contagious? |
Krystian Aparta
The English transcript was updated on 2/13/2015.