Belly laughter is considered the most honest type of laughter. It may also be the hardest type to experience, because we have to find something truly hilarious before we'll let go with the kind of laughter that has us clutching our bellies and gasping for air.
Of course, that's not the only description for true belly laughter; as you might guess, we all laugh differently. In a study conducted by Vanderbilt University, researchers found that men are more likely to grunt or snort at something they find funny, while women let loose with giggles and chuckles [source: Vanderbilt].
It's good to take note of what tickles your funny bone, however, because it just might save your life. In the 1979 book, "Anatomy of an Illness," Norman Cousins writes of how he used laughter to fight an illness that doctors told him was near incurable.
Cousins wrote, "Ten minutes of genuine belly laughter had an anesthetic effect and would give me at least two hours of pain-free sleep" [source: McCarthy]. Cousins turned to the Marx Brothers and "Candid Camera" and experienced a full recovery.