Animal laughs no joke says expert
Laughter may not be unique to humans.
Many animals may have their own forms of laughter, says a US researcher writing in the magazine Science.
Professor Jaak Panksepp says that animals other than humans exhibit play sounds that resemble human laughs.
These include the panting sounds made by chimps and dogs when they play and chirping sounds observed in rats.
This suggests that the capacity for laughter may be a very ancient emotional response that predates the evolution of humankind, says Panksepp.
Research suggests the capacity for human laughter preceded the capacity for speech.
Professor Panksepp, of Bowling Green State University in Ohio, US, explains that neural circuits for laughter exist in "ancient" parts of our brain, whose general structure is shared amongst many animals.
Young chimps "play pant" as they mischievously chase and tickle each other.
And when rats play, they make chirps which some scientists associate with positive emotional feelings. When rats are tickled in a playful way, they become socially bonded to humans and are rapidly conditioned to seek tickles, the US neuroscientist explains in Science. ..cont'd
http://news.bbc.co.uk/1/hi/sci/tech/4401695.stm