Research shows that the average adult laughs six to eight times a day... whereas the average child laughs around four hundred times each day. Today’s Please Explain is all about laughter. Dr. Robert Provine of the Neuroscience Program at the University of Maryland Baltimore County is author of the book Laughter: A Scientific Investigation.

Weigh in: What always makes you laugh...without fail? A person, a joke, a situation? Tell us by leaving a comment below.

Laughter is available for purchase at amazon.com