It is perhaps the most curious of involuntary bodily responses, that is, to giggle and guffaw with reckless abandon when our feet, armpits, and ribs are touched in just the right way. To be tickled seems to conjure equal parts ecstasy and turmoil, though it manifests itself as the purest expression of unsolicited joy -- laughter.
On its face, this bemusing phenomenon might seem a uniquely human tendency, yet for the last several years real scientists have been discovering tickle-induced chuckling all throughout the Animal Kingdom and are beginning to better understand the origins of laughter.
According to the BBC, researchers in the UK have essentially invented for themselves what might be the greatest job in the world: ticklin' for science. Their focus has been on how gorillas at a local wildlife park vocalize in response to some well-placed fingertip rub downs in order to learn more about how laughter may have evolved in humans. What they found were more similarities than differences, says Dr. Marina Davila-Ross of the University of Portsmouth.
"I was amazed about the way apes responded to being tickled - the apes seem to behave in the same way humans and children behave when they are being tickled," she told the BBC. "Based on the study, we can now say laughter is at least 30 million to 60 million years old."
This latest study with gorillas is just part of a surprisingly well-researched look into animals being tickled. In fact, when not eliciting laughter from a variety of species big and small in the lab themselves, scientists have discovered a wealth of animal-tickling videos on the internet with which to aid their studies. With that in mind, Davila-Ross believes science has honed in on laughter as an evolutionary advantageous 'positive expression' that helped social species better communicate with one another.
"A direct comparison across a range of species will give us some interesting insights into the evolution and co-evolution of play vocalisations and positive animal emotion," says the researcher.
Now, for some more videos of animals being tickled -- for your deeply analytical, science-minded enjoyment, of course.