Apes Laugh Too, Study Finds

Posted on June 11, 2009 in Animals, Recent Studies

Looks like humans aren’t the only species with a sense of humor: Researchers tickled apes and found that the sounds they made were similar to human laughter. The findings support evidence that human laughter grew out of primate roots.

The first formal study of how apes respond to tickling was conducted by scientists at the University of Portsmouth in England and published in the journal Current Biology. The experiment involved tickling 21 orangutans, gorillas, chimps and bonobos and human infants in order to chart the similarities between sounds. Then they mapped out an acoustic family tree of human and great ape laughter. Results showed that laughter is not a uniquely human trait.

Although the ape laughter sounded much different from human versions, the researchers determined that the distinctive features may come from a shared ancestor which lived 10 to 16 million years ago. Humans have evolved much more rapidly than apes over the last five million years, which accounts for the marked differences in laughter.
Like humans, gorillas and bonobos only exhaled while laughing, although their exhaling breaths lasted three or four times longer than breathing. This type of breath control, which is thought to be important in speech evolution, was also considered to be unique to humans.