Researchers from a Portsmouth University study believe that laughter links humans and apes and can be traced back between 10 and 16 million years.
Three human babies and 21 young apes from four species (orangutans, gorillas, chimpanzees and bonobos) were tickled by staff to build a library of 800 recordings of laughter, which were analysed and compared.
By measuring 11 traits in the sound, the study found that similarities and differences in laughter patterns correspond closely to genetic relatedness of species. This suggests that laughter in each species has a shared origin in a single ancestor.
“Our results on laughter indicate its pre-human basis. It is likely that great apes use laughter sounds to interact in similar ways to humans,” said Dr Marina Davila Ross.