Human-Ape Links Heard in Laughter
The ongoing search for our evolutionary links with the great apes picked up some clues with the study of laughter. Laughter is a universal trait of humans and also occurs in the primates like bonobos and gorillas. A study conducted at the University of Portsmouth, UK studied the laughter of a range of primates. It seems that the closer genetically to humans the primates are, the more similar their laughter is.
Human laughter is rooted in the emotional displays of the common ancestor we share with apes, suggests an analysis of the vocalizations of tickled juvenile apes and humans.
A team led by psychologist Marina Davila Ross of the University of Portsmouth, UK, undertook the task of tickling 25 young apes and humans, and recorded the resulting laughter (see video). They report this week in Current Biology that similarities between the acoustic characteristics of each species' laughter roughly reflects their genetic relatedness1.
"Particularly the gorilla and the bonobo could produce [human-like] sounds while breathing out for more than 10 seconds," says Davila Ross. The more distantly related orangutan and siamang's laughter, meanwhile, was correspondingly distinct.
A NP story discusses laughter among the orangutans.