Ken Jennings is best known as a record-setting Jeopardy! champion (74 wins, $2.5 million), podcaster, and genial hometown intellectual hero. Until now, his work as a writer has mainly consisted of educationalish books related to his passions for trivia and geography. His latest, however, is an ambitious work of pop sociology for adults.

Planet Funny: How Comedy Took Over Our Culture examines the pervasive and sometimes pernicious degree to which comedy has evolved from an entertainment category into the dominant mode of public and private expression among humans.

The insights are sharp, witty, and sometimes startling. Jennings is equally adept at citing Cicero and Allen Funt, at zooming in on the inflation of jokes-per-minute in the past 40 years of sitcoms or spinning out on the relationship between Twitter—with its weird split screen of casual cruelty humor and performed hypersensitivity—and the election of certain presidents.

Like any honest book published in 2018, Planet Funny does ever so slightly make you want to jump off a bridge. The way only a good book can. Jennings is neither condemning nor celebrating, but his angle on the comedification of discourse has complex implications—particularly if you've spent a lifetime investing in the view of yourself as a funny person.

"I don't feel like it has made me a better person to be 'the funny guy,'" Jennings told me over lunch recently. "When that's kind of baked into your identity, and you see it work for you in second grade or whatever, it becomes a big part of who you are. It wasn't until recently seeing it in my teenage son, and people would be like, 'Oh, he's sarcastic like you.' And it was just a knife to the heart."

Not because he doesn't appreciate a well-deployed bit of sarcasm, but because he began to recognize the way reflexive sarcasm had become less a suit of armor than an anchor weighing him down.

"This idea that I could glide through life with a smile and a quip was so woefully inadequate as soon as something bad actually happened," he said. "And you're seeing it now on Twitter in the Trump era, too. All these people who can tell a joke but now don't know how to act when it turns out things are not just benignly getting better all the time."

"Mastering that kind of snarky, disinterested voice is just a matter of mimicry. Because you hear it everywhere. A couple of comedians told me that: Anybody can do their voice of comedy and it sounds like they're doing jokes. But they're not doing jokes; they're just being sour."

And the sourness, when replicated constantly, in works of art or even just in person, can linger.

"I think what it's doing to our culture is kind of banishing earnestness," he said, "and diminishing the pleasure we take from jokes, because there's just too many to appreciate. There's the hedonic treadmill. We need more and more, weirder and weirder to make us laugh."

Ken Jennings would be the last person to suggest that a world without comedy is the answer. Not that it's an option. "I'm just trying to get across that it's going to be hard to deescalate," he said, chuckling.