科学美国人60秒 当主人归家时 狗狗为啥会眼泪汪汪？

This is Scientific American’s 60-Second Science. I’m Karen Hopkin.

这里是科学美国人——60秒科学系列，我是凯伦·霍普金。

After an exhausting day at the office, it’s hard not to smile when you’re greeted by a delirious¹ display of uncontrolled canine² joy.

在办公室度过了疲惫的一天后，当你看到狗狗们疯狂地表现出无法控制的喜悦时，你很难不会微笑。

But it’s not just the happy yapping and wriggling³ tail wagging that tug⁴ at our heartstrings.

但牵动我们心弦的不仅仅是欢快的叫声和扭动的尾巴。

Because a new study shows that dogs’ eyes fill with tears when reunited with their people--an effect that evokes⁵ our nurturing⁶ instincts.

因为一项新的研究表明，当狗狗与它们的家人团聚时，它们的眼睛里会充满泪水--这种效果唤起了我们的养育本能。

The findings appear in the journal Current Biology.

这项研究结果发表在《当代生物学》杂志上。

Takefumi Kikusui became interested in doggies’ damp and adoring gazes while watching his pet poodle interact with her pups.

Takefumi Kikusui在观察宠物贵宾犬与它的小狗互动时，他对狗狗们眼泪汪汪和充满崇拜的眼神产生了兴趣。

When she was nursing her puppies, her face becomes so cute.

当贵宾犬给自己的小狗喂奶时，它的脸变得如此可爱。

Of course she’s so cute as always. But more.

当然，它一直都很可爱。但是比以往更可爱了。

At some point Kikusui, who’s a professor of veterinary medicine at Azabu University in Japan, realized that his adorable mama dog had tears in her eyes.

Kikusui是日本麻布大学的兽医教授，在某个时候，他意识到可爱的狗妈妈眼里含着泪水。

That potential connection between unbearable⁷ cuteness and unshed tears sent Kikusui scurrying⁸ away from his poodle and back to the lab.

招架不住的可爱与打转的眼泪之间的潜在联系让Kikusui匆匆离开他的贵宾犬，回到实验室。

In the test, we initially⁹ measure the baseline tear volumes when dogs were together with the owner in their house.

在测试中，我们首先测量了狗狗和主人在一起时的泪水基本量。

Then the owner would high-tail it off for five or six hours.

随后主人就会在五到六个小时后迅速离开小狗。

When the owner came back, we measure tear volume again.

当主人回来时，我们又测量了一次泪液量。

And found that the reunion with the owner stimulate¹⁰ tear secretion¹¹.

发现与主人团聚会刺激泪液分泌。

But it only worked with the dog’s owner.

但这只对狗狗的主人有效。

There was no increase in tears when the dogs were separated from the owner and reunited with the dogs’ caretaker in a dog care center.

当狗狗与主人分开，在看护中心与其看护人团聚时，它们的眼泪并没有增加。

The researchers suspected that the tearful reaction was stimulated¹² by oxytocin--a hormone¹³ associated with social bonding.

研究人员怀疑，流泪的这种反应是由催产素刺激的，催产素是一种与社会联系有关的激素。

They had shown previously¹⁴ that oxytocin is boosted when dogs interact with their owners.

他们之前已经证明，当狗狗与主人互动时，催产素会增加。

And oxytocin receptors have been found to be abundant in the glands¹⁵ that secrete¹⁶ tears in mice.

人们已发现催产素受体在小鼠分泌泪液的腺体中含量丰富。

So we applied¹⁷ oxytocin to the dogs’ eyes.

所以我们把催产素涂在了小狗的眼睛上。

And voila…the dogs grew weepy.

瞧，这些狗狗们变得眼泪汪汪。

But to what end?

但这样的目的是什么呢?

In other words, is there some benefit to this lachrymose¹⁸ behavior?

换句话说，这种流泪的行为会有什么好处吗?

To find out, Kikusui and his colleagues showed volunteers a couple of hound head shots.

为了找到答案，Kikusui和他的同事们向志愿者们展示了一对猎犬的头部照片。

One was a normal dog face.

一张是正常的狗脸。

And the other was teary dog face in which we added artificial tears.

另一张是泪汪汪的狗脸，我们在狗脸上添加了人造眼泪。

The volunteers were more likely to want to cuddle and care for the mutts with big, wet puppy-dog eyes--

志愿者们更愿意拥抱和照顾那些眼睛大大的、眼泪汪汪的小狗--

--suggesting that teary eyes of dogs can facilitate the human caregiving behavior.

--这表明狗狗流泪的眼睛可以促进人类的照顾行为。

So dogs turn on the waterworks and their owners roll over.

所以当狗狗的眼睛开始流泪，它们的主人就会翻身照顾它们。

Now, that’s quite a clever trick!

此时，这是一个相当聪明的技巧!

For Scientific American’s 60-Second Science, I’m Karen Hopkin.

谢谢大家收听科学美国人——60秒科学。我是凯伦·霍普金。

Thank you for listening.

感谢收听。

1 delirious   

adj.不省人事的，神智昏迷的

参考例句：

• He was delirious,murmuring about that matter.他精神恍惚，低声叨念着那件事。
• She knew that he had become delirious,and tried to pacify him.她知道他已经神志昏迷起来了，极力想使他镇静下来。

2 canine   

adj.犬的，犬科的

参考例句：

• The fox is a canine animal.狐狸是犬科动物。
• Herbivorous animals have very small canine teeth,or none.食草动物的犬牙很小或者没有。

3 wriggling   

v.扭动，蠕动，蜿蜒行进( wriggle的现在分词 )；（使身体某一部位）扭动；耍滑不做，逃避（应做的事等）；蠕蠕

参考例句：

• The baby was wriggling around on my lap. 婴儿在我大腿上扭来扭去。
• Something that looks like a gray snake is wriggling out. 有一种看来象是灰蛇的东西蠕动着出来了。 来自辞典例句

4 tug   

v.用力拖(或拉)；苦干；n.拖；苦干；拖船

参考例句：

• We need to tug the car round to the front.我们需要把那辆车拉到前面。
• The tug is towing three barges.那只拖船正拖着三只驳船。

5 evokes   

产生，引起，唤起( evoke的第三人称单数 )

参考例句：

• The film evokes chilling reminders of the war. 这部电影使人们回忆起战争的可怕场景。
• Each type evokes antibodies which protect against the homologous. 每一种类型都能产生抗同种病毒的抗体。

6 nurturing   

养育( nurture的现在分词 )； 培育； 滋长； 助长

参考例句：

• These delicate plants need careful nurturing. 这些幼嫩的植物需要精心培育。
• The modern conservatory is not an environment for nurturing plants. 这个现代化温室的环境不适合培育植物。

7 unbearable   

adj.不能容忍的；忍受不住的

参考例句：

• It is unbearable to be always on thorns.老是处于焦虑不安的情况中是受不了的。
• The more he thought of it the more unbearable it became.他越想越觉得无法忍受。

8 scurrying   

v.急匆匆地走( scurry的现在分词 )

参考例句：

• We could hear the mice scurrying about in the walls. 我们能听见老鼠在墙里乱跑。 来自《现代英汉综合大词典》
• We were scurrying about until the last minute before the party. 聚会开始前我们一直不停地忙忙碌碌。 来自辞典例句

9 initially   

adv.最初，开始

参考例句：

• The ban was initially opposed by the US.这一禁令首先遭到美国的反对。
• Feathers initially developed from insect scales.羽毛最初由昆虫的翅瓣演化而来。

10 stimulate   

vt.刺激，使兴奋；激励，使…振奋

参考例句：

• Your encouragement will stimulate me to further efforts.你的鼓励会激发我进一步努力。
• Success will stimulate the people for fresh efforts.成功能鼓舞人们去作新的努力。

11 secretion   

n.分泌

参考例句：

• Is there much secretion from your eyes?你眼里的分泌物多吗？
• In addition,excessive secretion of oil,water scarcity are also major factors.除此之外，油脂分泌过盛、缺水也都是主要因素。

12 stimulated   

a.刺激的

参考例句：

• The exhibition has stimulated interest in her work. 展览增进了人们对她作品的兴趣。
• The award has stimulated her into working still harder. 奖金促使她更加努力地工作。

13 hormone   

n.荷尔蒙，激素，内分泌

参考例句：

• Hormone implants are used as growth boosters.激素植入物被用作生长辅助剂。
• This hormone interacts closely with other hormones in the body.这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。

14 previously   

adv.以前，先前（地）

参考例句：

• The bicycle tyre blew out at a previously damaged point.自行车胎在以前损坏过的地方又爆开了。
• Let me digress for a moment and explain what had happened previously.让我岔开一会儿，解释原先发生了什么。

15 glands   

n.腺( gland的名词复数 )

参考例句：

• a snake's poison glands 蛇的毒腺
• the sebaceous glands in the skin 皮脂腺

16 secrete   

vt.分泌；隐匿，使隐秘

参考例句：

• The pores of your body secrete sweat.身上的毛孔分泌汗液。
• Squirrels secrete a supply of nuts for winter.松鼠为准备过冬而藏坚果。

17 applied   

adj.应用的；v.应用，适用

参考例句：

• She plans to take a course in applied linguistics.她打算学习应用语言学课程。
• This cream is best applied to the face at night.这种乳霜最好晚上擦脸用。

18 lachrymose   

adj.好流泪的，引人落泪的；adv.眼泪地，哭泣地

参考例句：

• She waxed lachrymose.她伤心起来了。
• Maybe if you moved away from Lake Lachrymose you might feel better.也许搬离这悲哀之湖会让你好受一些。