Scientists suspect that the panting behavior exhibited by dogs during "play chasing" is an analog for human laughter.
It's no joke: Even animals ‘laugh’
Expert says dogs pant and rats chirp to express mirth
By Robert Roy Britt
Senior writer
Life can be funny, and not just for humans.
Studies by various groups suggest monkeys, dogs and even rats love a good laugh. People, meanwhile, have been laughing since before they could talk.
"Indeed, neural circuits for laughter exist in very ancient regions of the brain, and ancestral forms of play and laughter existed in other animals eons before we humans came along with our 'ha-ha-has' and verbal repartee," says Jaak Panksepp, a neuroscientist at Bowling Green State University.
When chimps play and chase each other, they pant in a manner that is strikingly like human laughter, Panksepp writes in Friday's issue of the journal Science. Dogs have a similar response.
Rats chirp while they play, again in a way that resembles our giggles. Panksepp found in a previous study that when rats are playfully tickled, they chirp and bond socially with their human tickler. And they seem to like it, seeking to be tickled more. Apparently joyful rats also preferred to hang out with other chirpers.
The first laugh
Laughter in humans starts young, another clue that it's a deep-seated brain function.
"Young children, whose semantic sense of humor is marginal, laugh and shriek abundantly in the midst of their other rough-and-tumble activities," Panksepp notes.
Importantly, various recent studies on the topic suggest that laughter in animals typically involves similar play chasing. It could be that verbal jokes tickle ancient, playful circuits in our brains.
More study is needed to figure out whether animals are really laughing. The results could explain why humans like to joke around. And Panksepp speculates it might even lead to the development of treatments for laughter's dark side: depression.
MSNbc3月31日讯，专家称狗气喘吁吁或老鼠吱吱叫是它们开心的表现。生活总是充满了各种各样可笑的事情，而且绝不仅限于人类社会。
许多研究组织的研究结果表明、猴子、狗甚至老鼠都喜欢笑。
“实际上，笑的神经回路存在大脑中的历史已经十分久远，而且其它动物大脑中存在的玩耍和笑的遗传性要比在我们人类学会发出‘哈哈哈’笑声、开始使用语言早无数年，” 美国保令格林州立大学的神经学科学家潘克斯普说。
当黑猩猩相互游戏追逐时，它们会开始喘粗气，而且喘气的声音和人类的笑声极为相似，狗也有相似的情形，潘克斯普在本周五版的科学期刊上写到。
老鼠在玩耍时也会吱吱叫，听起来有些像人在咯咯笑一样。潘克斯普以前也曾发现，如果在玩耍时给小老鼠搔痒，它们会开始吱吱叫并且会和给自己搔痒的人变得很亲近。看起来它们喜欢搔痒，很显然开心的小老鼠也喜欢和其它吱吱叫的小老鼠一起玩。
第一次笑
人类笑的活动在很小时就会开始，这也就是说这种活动是深深根植于我们大脑中的。
“对于很小的孩子，他们的对言语幽默的反应还是零，但是他们在跌跌撞撞的活动过程中常常会大笑或者咯咯笑，” 潘克斯普强调说。
重要的是，近期的各种相关研究表明，动物在发笑的时候往往伴随着追逐玩耍。对于人类来说，很有可能是诙谐的言语“搔”动了我们大脑中存在已久的“玩耍神经回路”。
要证实动物到底会不会笑，科学家们还需要进行更多大量的研究。研究结果很由可能会解答人类为什么会喜欢开玩笑这种行为。潘克斯普推测说，这个问题很有可能会延伸到开发针对笑的对立面——抑郁症的治疗方法。
笑声背后的进化原因
同时，还有一个问题，究竟是什么东西是动物们的世界如此可笑。
“虽然现在还没有人研究老鼠之间幽默存在的可能性，如果它存在的话，这很有可能与嬉戏有密切的关系，” 潘克斯普认为。“就算成年的啮齿动物没有发展健全的认知幽默的能力，年幼的老鼠也可能拥有不同寻常的快乐感。”
而人类科学传统上是认为动物不可能有感觉喜怒哀乐的能力。
潘克斯普对于这个看法的回答是：“虽然有些人仍然认为笑使人类都有的特性，但是事实上，自从更新世时期开始，它们就已经有这种能力了。”
