NEW YORK (AP) – Humans and great apes have been giggling in similar ways since branching off the evolutionary tree, a new study suggests.

The rhythmic patterns of laughter found in apes and humans reveal that complex primate vocal control might have started evolving 15 million years ago.

A study of 140 laughter sequences found the same rhythmic timing pattern in humans, chimps, gorillas, bonobos and orangutans.