If you have a dog, you may have noticed that sometimes it seems to be smiling.
如果你养狗,你可能已经有所发觉，这只汪星人有时似乎在微笑。
But, of course, we know that dogs don't really smile.
但是,当然,我们清楚狗是不会笑的。
That's just how dog mouths appear sometimes, right?
狗狗的嘴有时会张开，对吗?
Perhaps, but according to neuroscientist Jaak Panksepp of Bowling Green State University, some animals do laugh.
也许的确如此,但按照博林格林州立大学神经系统科学家贾克·潘克斯皮的理论,一些动物确实会笑。
When chimps play, Panksepp notes, they make panting sounds that could be a form of laughter.
当黑猩猩玩耍的时候, 潘克斯皮指出,他们发出气喘吁吁的声音可能就是一种形式的笑声。
Even rats have a way of laughing-by chirping when they're playing with each other or being tickled by humans.
即使老鼠也有办法—彼此嬉戏或被人类逗乐时候通过鸣叫就可以愉悦自己。
But, if animals do in fact laugh, what are they laughing at?
但是,如果动物事实上真的在笑,他们是在笑什么?
Scientists have long known that for many animals, life isn't all about hunting, foraging, fighting, and sleeping.
科学家已经知晓对于许多动物而言,生活不仅仅是狩猎,觅食,争斗及睡觉。
Young animals also play a lot, which suggests that animal laughter is related to playful joy.
年轻的动物也会玩耍,这意味着动物笑的原因与嬉戏快乐有关。
How is this possible?
这怎么可能?
Human laughter originates in very ancient areas of the brain.
人类的笑声起源于大脑非常古老的区域。
This suggests that mammalian brains were wired for playful joy long before the rise of modern humans.
这表明,哺乳动物的大脑在现代人类崛起前就已经对嬉戏快乐有所感觉。
So it's not too much of a stretch to claim that pre-human forms of laughter may exist.
因此,对于可能存在的远古人类的笑没有太多的观点延伸。
To be clear, it's not certain that animals really laugh like humans, at least not in response to humor.
需要明确的是,动物的笑不一定像人类一样,至少不是对幽默的回应。
However, many studies suggest that animals are capable of complex emotions such as fear, anger, and even joy and sadness.
然而,许多研究表明,动物本身拥有如恐惧、愤怒,甚至快乐和悲伤等复杂的情绪。
So your dog's grin may not be a real human-type smile.
所以你的狗狗咧开嘴并不是真正意义的微笑。
But it now seems likely that deep in brain regions that animals share with humans, the ability for joy and ancients forms of laughter do exist.
但现在看来动物和人类共享大脑的深处区域,高兴的能力及远古笑的形式的确存在。
