評論
打印
Let's say it's getting late, you're studying with a group of friends around a table,
假設現在已經很晚了，你和一群朋友圍坐在桌子旁學習，
and you see one of them stretch and yawn.
這時，你看到一個人伸腰打了個哈欠。
You don't feel especially tired, but soon enough, without even realizing it, you yawn too.
你感覺不是特別累，但不久，也不知不覺得打了個哈欠。
Then, the yawn spreads around the table,
然后，哈欠在桌子四周的人群中擴散開來，
with more and more of your friends picking it up unconsciously.
越來越多的朋友開始不自覺得打哈欠。
This sort of contagion can happen with other things, like sniffing or laughter,
這種傳染可以發生在其他事情上，比如吸氣或大笑，
and it has baffled psychologists for a while.
這讓心理學家困惑了一段時間。
Most scientists agree that these so-called echophenomena exist,
大多數科學家都同意所謂的模仿現象存在，
but there are a couple different hypotheses about why they happen.
但是關于它們的起因有幾個不同假設。
Several clues come from studies looking at what kinds of animals and people actually catch yawns.
對什么樣的動物與人類能傳染哈欠的觀察研究得出了幾條線索。
We've only seen contagious yawning in certain species,
我們只發現傳染性哈欠在特定物種中出現，
like humans, chimpanzees, baboons, and in response to us, dogs.
比如人類、 黑猩猩、狒狒以及回應我們的狗。
These are all very social animals, creatures whose survival depends on working together
它們都是群居動物，通過共同工作來生存，
and being sensitive to each other's needs.
對彼此的需求很敏感。
And that might not be a coincidence.
這可能不是巧合。
One idea is that contagious yawning is related to empathy,
一個觀點是傳染性哈欠與同理心
or the ability to put yourself into someone else's shoes.
或者是設身處地為別人著想的能力有關。
Various studies have repeatedly shown that people who have impaired social skills,
各種研究一再表明，社會技能受損的人
including those with autism and schizophrenia,
包括那些患有自閉癥和精神分裂癥的人，
are less likely to yawn sympathetically than their peers.
與同齡人相比，打哈欠的可能性更小。
And kids below the age of four are also much less susceptible to contagious yawning than older children or adults.
4歲以下的兒童比大孩子或成人更不易受傳染性哈欠的影響。
Psychologists also point to experiments that find yawning is more contagious
心理學家還指出，實驗發現，如果最初打哈欠的人離你較近，
if the original yawner is someone close to you.
你會更容易傳染打哈欠。
Both chimpanzees and humans are more likely to yawn if they see someone familiar yawn, versus a stranger.
黑猩猩和人類如果看到熟悉的同類打哈欠，會比看到陌生同類更容易傳染打哈欠。
Since we tend to be more empathetic to members of our own group,
因為我們對自己群體的成員更有同感，
this bias suggests that contagious yawning could be rooted in empathy.
這種偏見表明，傳染性哈欠可能根植于同理心。
That being said, a more recent study in autistic children found that their inability to catch a yawn
話雖如此，最近一項針對自閉癥兒童的研究發現，他們沒有能力去傳染呵欠，
might be because they're not looking at people's faces, rather than a lack of empathy.
這可能是因為他們不看別人的臉，而不是缺乏同理心。
In two sets of experiments with about two dozen children with autism,
在針對24名自閉癥患兒的兩組實驗中，
about 30% yawned contagiously, the same rate as developmentally normal children
如果患兒被告知要數一下打哈欠人的胡子或眼鏡，
if they were told to count the beards or glasses of the people yawning.
那么大約30%的人會傳染性地打哈欠，這一概率與發育正常的兒童相同，
In other words, if the kids were directed to look at the faces, they became just as likely to yawn.
換句話說，如果孩子們被引導著去看臉，他們很可能會打哈欠。
But for scientists who think that empathy plays at least some part in contagious yawning,
科學家認為同理心至少在傳染性哈欠方面有些作用，對他們來說，
one hypothesis is that mirror neurons are involved in the brain.
有種假設是鏡像神經元與大腦有關。
These neurons form networks
這些神經元形成網絡
and are thought to fire if a person is doing a task or watching someone else do the same task.
如果一個人在做一項任務或者看別人做同樣的任務時，它們會被激活。
This way, the thinking goes, the neurons "mirror" those actions and can help with mimicry, and maybe empathy.
這種思維方式是，神經元“反映”這些行為，并能幫助模仿它們，或許還能感同身受。
In support of this, a handful of small fMRI studies have found
為了支持這一點，幾個小型功能磁共振成像（fMRI）研究發現，
that mirror neurons light up when volunteers watch videos or listen to sound recordings of other people yawning.
當志愿者觀看視頻或聽其他人打哈欠的錄音時，鏡像神經元會激活。
But as appealing as this idea is, some scientists aren't so sure that mirror neurons are responsible.
盡管這個想法很吸引人，但一些科學家仍不確定鏡像神經元是否有責任。
Other fMRI studies of contagious yawning haven't seen any mirror neuron activation.
其他關于傳染性哈欠的fMRI研究還沒有發現任何鏡像神經元的激活現象。
And neuroscientists are still debating the function and location of mirror neurons in the human brain.
神經科學家們還在討論鏡像神經元在人腦中的功能和位置。
A different way scientists explain contagious yawning is simply that motor areas of the brain,
科學家對傳染性哈欠的另一種解釋是大腦的運動區域
like the ones that control your facial movements, are easily excitable.
比如控制你面部運動的區域，很容易興奮。
A study published this past summer measured the excitability of motor neurons in three dozen people
去年夏天發表的一項研究測量了30多人
while they watched videos of others yawning.
在看其他人打哈欠視頻時的運動神經元的興奮性，
They used a technique called transcranial magnetic stimulation, or TMS,
他們使用了一種叫做經顱磁刺激（TMS）的技術，
in which a coil that's generating a magnetic field is passed across the head.
它的線圈產生的磁場能穿過頭部。
And this magnetic field can be used to stimulate and measure electrical signals in neurons.
這個磁場可以用來刺激和測量神經元中的電信號。
The researchers found that people with more natural activity in those neurons were more likely to yawn.
研究人員發現，這些神經元中有更多自然活動的人更容易打哈欠。
In fact, differences in neuronal activity explained about half of the variation in whether a person yawned or not.
事實上，神經元活動的差異解釋了一個人打哈欠與否的一半變化。
And when some other scientists tested for correlations between empathy test scores and catching yawns,
當其他一些科學家測驗同理心測試得分和傳染哈欠之間的相關性時，
they also found that different people might just have inherently different susceptibility.
還發現不同的人可能天生就有不同的易感性。
In one study of more than 300 adults,
在一項針對300多名成年人的研究中，
researchers showed participants a 3-minute video of other people yawning.
研究人員讓參與者看了一段其他人打哈欠的3分鐘視頻。
How likely a person was to yawn in response didn't have anything to do with how empathetic they were.
一個人打哈欠的可能性與他們的同理心沒有任何關系。
Instead, it was more related to age, with younger adults yawning more than middle-aged or older adults.
相反，它與年齡更相關，年輕人的哈欠超過了中年或老年人。
Also, the scientists noticed that each person seemed to have a hardwired level of sensitivity to contagious yawning.
此外，科學家們注意到，每個人似乎對傳染性哈欠都有一種天生的敏感度。
Some people yawned a lot over multiple sessions,
有些人在多次會議上打了很多哈欠，
and others never opened their mouths at all.
有些人根本就沒開口。
These results jive well with the motor neuron excitability idea,
這些結果支持運動神經元興奮性的觀點
although they still leave a lot of questions unanswered,
盡管仍有許多懸而未決的問題，
like why we've evolved this reaction in the first place.
比如為什么我們一開始就進化了這個反應。
In any case, for a lot of us, it doesn't take much to yawn if we see someone else do it.
無論如何，對于我們很多人來說，它對我們看到其他人打哈欠沒有多大影響。
There's even a good chance a lot of you automatically yawned just while watching this video.
在觀看這段視頻的時候，很多人會自動打哈欠。
And if you haven't yet, I'll give you one more reason.
如果你還沒有，我再給你一個理由。
Thanks for watching this episode of SciShow Psych!
感謝您收看本期的心理科學秀！
If you want to learn more about this kind of stuff,
如果你想了解更多這方面的內容，
check out our video where Hank talks about a phenomenon called groupthink,
看看我們的視頻，漢克談到了一種叫做群體思維的現象，
which is basically how your friends can affect your opinions.
它基本上講得是你的朋友如何影響你的意見。
And don't forget to go to youtube.com/scishowpsych and subscribe!
不要忘了登錄youtube.com/scishowpsych點擊訂閱哦！
