The wit makes fun of other persons; the satirist makes fun of the world; the humorist makes fun of himself.
–James Thurber

My mom insists her autobiography will be titled I Laugh Alone, but she has always cracked me up. When I was little, a stranger showed up at our door with her daughter in tow, asking if they could come in and watch my dad write a song. Mom’s deadpan reply: “He does most of his writing on the john.” I laughed till it hurt while the stranger retreated, unamused.

Laughing alone can be painful. I once had a date with a smart saleswoman named Diane. When we got to talking favorite movies — a dangerous topic — it was all I could do not to burst out laughing before getting out the words Spinal Tap. Diane put the kibosh on our future with a frosty stare and an icy “Not funny.”

Sometimes tickling ourselves can get a bit macabre. Barry, a college classmate, sat down next to me in the dining hall early in our freshman year and, while slathering his mystery meat with ketchup, revealed that he sometimes applied the Heinz to his body and then lay out in the middle of the road. In the event, I doubt anyone saw the humor, but Barry’s tale set the stage for a lifelong friendship.

Of course, laughter is also serious business. Anthony J. Chapman and Hugh C. Foot’s weighty tome Human Laughter: Theory, Research and Applications defines it as “the inarticulate vocal sounds of a reiterated ha-ha variety.” Now that’s funny. Mating Intelligence — a 2007 compendium of academic papers on why humans choose their partners — devotes a chapter to “The Role of Creativity and Humor in Mate Selection.” The essay — which took no fewer than four masters of the obvious to write — cites a mountain of research leading to one portentous conclusion: “a good sense of humor is an important human mate preference worldwide.” (This level of rigor brings to mind the recent Oxford study which required an expenditure of 300,000 pounds to make the case that ducks like water.)

(Another chapter of Mating Intelligence — “Deception and Self-deception as Strategies in Short and Long-Term Mating” — was written by Maureen O’Sullivan. Could she be a descendant of the namesake who advanced our understanding of mating intelligence as an evolutionary force by playing Jane to Johnny Weissmuller’s Tarzan?)

Evolutionary humor cuts both ways. Former neuroscientist Wendy Northcutt has built a cottage industry — via New York Times best-selling books and the thriving website www.DarwinAwards.com — around the notion of honoring those who “improve our gene pool by removing themselves from it in a sublimely idiotic fashion.” Case in point: the owner of an equipment training school who demonstrates the dangers of driving a forklift by failing to survive the filming of his own safety video.

Spontaneous laughter can be a universal tonic. I’ve been privileged to spend time with the autistic son of a friend. Watching him shift in a nanosecond — and with no apparent stimulation — from utter silence to spontaneous glee has been contagious and inspiring. Images of the laughing Buddha are a staple of Zen art; this might be explained — or non-explained — by these words of Tibetan meditation master Long Chen Pa: “Since everything is but an apparition, perfect in being what it is, having nothing to do with good or bad, acceptance or rejection, one may well burst out in laughter.” Could it be that my autistic friend and the Buddhists are marveling at the same crazy, cosmic wondrousness?

In the end, we’re in serious trouble unless we can — literally — make fun of ourselves. I’ve been lucky my parents shared that trait — and had the mating intelligence to find each other. When my dad emerged from double-bypass surgery shortly before he died in 2000, he was so out of it I doubt he knew I — or anyone — was around. That didn’t seem to bother him, though. Perhaps contemplating an X-ray, he seemed satisfied to amuse himself by quipping, “Aorta be in pictures.”