Great apes have been laughing with the same rhythmic structure as modern humans for at least 15 million years, a new study reveals. While our laughter became faster and more consciously controlled over time, this shared primitive rhythm provides a rare window into how human speech evolved.

Great apes have been laughing with the same rhythmic structure as modern humans for at least 15 million years, a new study reveals. While our laughter became faster and more consciously controlled over time, this shared primitive rhythm provides a rare window into how human speech evolved.