Scientists tickled monkeys to find if they have the same giggles as humans — and they do

Scientists tickled 13 captive apes and compared their laughter to that of four children, finding similar rhythmic patterns suggesting a shared evolutionary origin. The study, led by Chiara De Gregorio, indicates human and great ape laughter has followed similar rhythms for 15 million years, with human laughter evolving to become faster and more context-dependent.