My three young daughters like to watch pets doing silly things. Almost daily, they ask to see animal video clips on my phone and are quickly entertained. But once my 7-year-old lets out a belly laugh, ...

We dare you not to crack a smile watching this girl laugh hysterically at her older sister! There is something so human and special when you hear a genuine uncontrollable laugh erupt. No one has a ...

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Long before modern brain imaging technologies illuminated the neurophysiological mechanisms that make laughter contagious, William James (1842-1910) observed, "We don't laugh because we're happy, ...