A baby orangutan called Naru laughs with delight as he is tickled by a keeper.
Credit: Miriam Wessels
Robert Provine, a neuropsychologist from the University of Maryland in Baltimore, USA, endorsed the study as a great piece of work and said that it correlated with some of his own findings. His research suggests that "the 'ha-ha' of human laughter evolved from the 'pant-pant', the laboured breathing, of our primate ancestors during tickling and rough-and-tumble play," he said.
"The article is interesting and important. It provides further evidence of an evolutionary scenario," added Provine.
Language link
Kai Alter, a neuroscientist at Newcastle University in England, also agreed that the results were exciting, but cautioned against overinterpretation. "The idea is an excellent one... there may indeed be a common evolutionary origin [for laughter] in humans and apes. However tickling is something different from other types of laughter such as taunt, scorn, schadenfreude and joy," he said.
The researchers behind the study said that the next step is to look into the implications of the findings for the origin of human language.
Speech and laughter share some characteristics - both require sustained airflow and are performed only while breathing out - so it's possible that the evolution of laughter was a precursor for the evolution of speech, said Davila-Ross.
