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The animal nature of spontaneous human laughter
"Laughter is a universally produced vocal signal that plays an important role in human social interaction."

The animal nature of spontaneous human laughter
"Laughter is a universally produced vocal signal that plays an important role in human social interaction. Researchers have distinguished between spontaneous and volitional laughter, but no empirical work has explored possible acoustic and perceptual differences."

UCLA's 'Laughter Guy' dissects features of counterfeiting chortling
"Ever wonder how often you fool your boss or in-laws by pretending to laugh at their dumb jokes?"