Quoted: It’s previously been argued that chimps chuckle, but their methodâ??”laughing” on both the exhale and inhaleâ??had been deemed too different from the human, exhale-only laugh.
The tickle study, however, found evidence that most ape laughter, especially among gorillas and bonobos, shares key traits with human laughter.
Like humans, for example, gorillas and bonobos laughed only while exhalingâ??leading University of Wisconsin zoologist and psychologist Charles Snowdon, who was not involved in the study, to conclude that, “contrary to current views, the exhalation-only laughter is not uniquely human but is found in our ape ancestors.”