Laughter:

Simler & Hanson:

"Laughter is an involuntary behavior. It's not something we actively decide to do; our brains simply do it[.] ... We use laughter to flirt, bond with friends, mock our enemies, probe social norms, and mark the boundaries of our social groups. ... and yet "we" - the conscious, deliberate, willful parts of our minds - don't get to decide when we do it."

"we're ... astonishingly unaware what laughter means and why we do it. Speculation abounds, but much of it is erroneous, and not just among laypeople. ... For a behavior we perform every day, it's shocking how alien laughter is to our conscious minds. But while "we" may not understand or control our laughter, our brains are experts at it. They know when to laugh, at which stimuli, and they get it right most of the time, with inappropriate laughter bursting forth only on occasion. Our brains also instinctively know how to interpret the laughter of others, whether by laughing in return or otherwise reacting appropriately. It's only to "us" - our conscious, introspective minds - that laughter remains a mystery."

----

"Laughter ... [is] relatively honest. With words, it's too easy to play lip service to rules we don't really care about, or values that we don't genuinely feel in our gut. But laughter, because it's involuntary, doesn't lie - at least not as much. "In risu veritas," said James Joyce; "In laughter, there is truth." "