Research suggests that the laughter of great apes may hold clues to the origins of human speech, with studies indicating that humans and apes have shared a similar laugh pattern for 15 million years. This shared laughter pattern is thought to reveal a hidden origin of human speech, with the rhythm of ape laughter potentially holding a 15-million-year-old secret. The findings imply a long-standing connection between ape and human communication, but the exact nature of this connection and its implications for the evolution of human speech are still being explored.