Sir Humphry Davy learned quite a bit from experiment in which he exposed animals — including himself — to laughing gas. One of the things he learned was how to look at blood and determine a cause of ...

When you hear someone laugh behind you, you probably picture them on the phone or with a friend – smiling and experiencing a warm, fuzzy feeling inside. Chances are just the sound of the laughter ...

If you just waved enthusiastically at a total stranger, science has some advice: chuckle, don't cringe. A series of six experiments involving more than 3,000 people, published in the Journal of ...