Tickling Induces a Unique Type of Spontaneous Laughter

A new study reveals that laughter induced by tickling is uniquely different from other types of laughter, both acoustically and perceptually. Researchers collected 887 spontaneous laughter clips from various real-life situations, including comedic performances and playful pranks. Using machine learning analyses, they found that tickling-induced laughter has distinct acoustic properties compared to other types of laughter. Furthermore, over 400 listeners accurately differentiated tickling-induced laughter from others, and rated them as involving less vocal control and being more involuntary. These findings highlight tickling as an evolutionarily ancient play behaviour and showcase how machine learning can reveal patterns in human behaviours.