Scientists Trace Origin of Human Laughter to 15-Million-Year-Old Common Ancestor

Comparative recordings of laughter from humans and great apes reveal that the distinctive rhythmic "ha ha ha" pattern likely originated in a shared primate ancestor dating back at least 15 million years. The finding suggests laughter evolved as a fundamental communication mechanism deep in primate evolutionary history, predating modern human language and social structures.

Why it matters: Understanding the evolutionary roots of human behavior and communication mechanisms informs AI researchers designing more human-like conversational systems and helps tech ethicists evaluate how artificial agents should interact with people.