Are humans the only primates that laugh?
Peter Ungar, professor of anthropology, replies:
As Charles Darwin wrote in 1872, apes “utter a reiterated sound, corresponding with our laughter, when they are tickled, especially under the armpits.” While non-human primates don’t likely have the capacity to appreciate complex jokes or puns, our nearest living relatives are often reported to laugh during tickling or chasing games. Chimpanzee and bonobo laughter even look and sound like ours to a degree. These apes show a relaxed “open-mouth” display resembling a smile, and exhibit similar changes in frequency and intensity of sounds while laughing. Many primatologists speculate that laughter evolved as a communications tool to help regulate social interactions.