Research suggests that great apes and humans share a similar laughter rhythm that may date back 15 million years, potentially shedding light on the origins of human speech. However, the scope of the study's findings is unclear, with some reports focusing on great apes and others mentioning unrelated animals, such as goats and sperm whales. The connection between great ape laughter and human speech is being explored, but the extent of the research and its conclusions are not entirely clear.