If 6,300 episodes of “Jeopardy!” count as scientific data, human beings can be classified as a cordial and sedate species, partial to demure wardrobes and simple haircuts. Each human displays a rigorous grasp of general knowledge and possesses both a typical occupation and a single succinct-yet-charming anecdote that defines his or her life. They enjoy using their knowledge to win modest amounts of money, three at a time, Monday through Friday, on a soundstage in Culver City, Calif.

There is a fourth human who remains apart, behind a lectern near a wall of flat-screen TVs. He is also cordial and sedate. He is the host of the show. He cracks few jokes. He hugs no one. He wears suits in gray and navy. He announces categories and reads clues and says “Right” or “Correct” or “Yes” and, sometimes, “No.” He has all the answers, which means he knows all the questions. He used to stand behind the lectern but now he sits. He used to have a mustache but now he doesn’t.

Three rounds, 13 categories, 61 pairs of answers and questions, 28 seasons, 13,000 contestants, one Alex Trebek. The master of the trivial. On television, anyway. In person . . .

“I was just reading something by Immanuel Kant about perpetual peace, and I’m looking at that, and it’s a great idea,” Trebek says, sitting in an armchair in the executive suite of the Capitol Hilton last week, a couple of days before taping the show’s “Power Players” edition in the District. “But I’ve got to read it about three or four times in order to figure out exactly the point he’s trying to make.”

You have Kant with you?

“Yeah I just printed it out because I was interested in something going on,” he says, his voice lowering, like he wants to change the subject.

What something?

“Well,” Trebek says, almost muttering, “just — the future . . . 

The future.

“How are we going to deal with the future,” he says without question marks. “How are we going to achieve peace.”

And here’s your host . . .

Here we have Alex Trebek. He’s a quiz-show host from Los Angeles. It says here that one of your earliest memories is breaking through thin ice on a creek in your native Sudbury, Ontario.

“Mid-winter,” Trebek says, in a hypnotized monotone. “When I was about 7 years old. My sister and a couple of her friends were playing on a frozen creek that was not frozen entirely. And I told her, ‘Get off the ice. It’s not safe. It’s too dangerous. I’ll check it out for you.’ And then the ice cracked under me, and I fell in.”

The boy dried off, learned his lesson, completed his French Canadian upbringing, majored in philosophy at the University of Ottawa, took a broadcasting job because it paid his tuition, went with the flow to California, knocked around in a half-dozen game shows in the ’70s and early ’80s (“Wizard of Odds,” “The New High Rollers”) and landed a winner in 1984. A reboot of the original version hosted by Art Fleming in the ’60s and ’70s, “Jeopardy!” was expected to last for six or seven seasons, according to its late creator, Merv Griffin, but ended up becoming a syndicated staple of Americana.

Trebek is 71. The past three decades have passed by in a blur, he says. He wanted to be many different things when he was growing up — actor, doctor, prime minister — but somehow ended up doing what he’s doing: presiding over five tapings every Tuesday and Wednesday, arriving at work at noonish and returning by 6 or 6:30 p.m. to his mansion in Studio City, his wife of 22 years and his 91-year-old mother. He spends the rest of the week traveling (he’s been to every continent except Australia), devouring television (“The Borgias” and “Law & Order” marathons) and books (he recently bristled at the iffy merits of Bill O’Reilly’s “Killing Lincoln”). He mentions, as he has in previous interviews, that he likes to fix his property’s aging sprinkler system. L.A.’s gurgly water pressure — which varies from 105 to 155 pounds per square inch, he says — strains the system’s old rubber diaphragms. Trebek talks about the sprinklers like Lennie talks about the rabbits or Norman Thayer talks about the loons on Golden Pond.

His two children are out of the house, in college.

His tan is perfection.

He tends the sprinklers.

“I don’t spend any time whatsoever thinking about what might have been,” he says when asked to imagine life without “Jeopardy!” “It is what it is. My life is what it is, and I can’t change it. I can change the future, but I can’t do anything about the past.”

“The Future.” The only category on the board that seems to challenge him. He’s worried that the United States has lost its reputation as the ultimate world power. He thinks politicians are mishandling their responsibilities. A staunch independent, Trebek says he’s refused donation requests from Republicans and Democrats and wishes “a pox on both their houses.” Audience members always ask if he’d run for office, but that’s one game he doesn’t want to play.

“When you’re in your 30s and actively pursuing a career and a home life, a wife and children, you’re busy doing as opposed to busy thinking,” he says, dissecting his own introspection. “As you get older, even as you don’t have as much time, I think you tend to think more and reflect more on what is happening in your own life.”

Question time

A vast scrim of the American flag encloses the stage. A grand colonnade frames the contestant lecterns. A hulking statue of a seated Lincoln, wooden but painted to look marble, watches the host move downstage at DAR Constitution Hall to meet his constituents. Hands shoot up and waggle.

“What did you have for breakfast this morning?” asks an audience member.

The host pauses, lost in thought.

“Probably a Twix,” Trebek says. “And a Diet Pepsi.”

Even when the cameras aren’t rolling, he talks in his soothing-yet-stilted hosting voice, as if he’s reading cue cards no one else can see. But he charms the audience with his affability and sharing of personal mundanities, which is the norm during “commercial breaks” in Culver City, too.

His contestants for the second of five “Power Players” tapings Saturday (the episodes air May 14-18) are Kareem Abdul-Jabbar, former White House press secretary Dana Perino and CNBC co-anchor David Faber. Before the taping begins, he chats with Perino, now a Fox News co-host, and asks whether he can take a tour of her employer’s headquarters the next time he’s in New York. He’d like to meet O’Reilly so he can “talk to him about his book.”

The taping begins. Cameras glide over spectators. “Applause” signs blink. When a contestant misses an easy answer, the audience ripples with alarm. When none of the contestants buzzes in, people look at each other, mouth the answer and shake their heads in gentle disappointment. This is the “Jeopardy!” nation, the nation of know-it-alls, or should’ve-known-it-alls, who are edified by knowing a triple stumper, who believe they’d have the confidence and courage to make it a true Daily Double.

Deep thoughts

Let’s go back to “German Philosophers,” Alex, for $1,000.

Kant’s “Perpetual Peace” anticipated, by 300 years, the American follies of the 21st century: Military entanglements in foreign lands (“What are Iraq and Afghanistan?”), a reckless credit system (“What is the subprime mortgage crisis?”), the cancer of political corruption (“What is Congress?”).

Consider modern American politics alongside modern American television, in which reality shows exploit humanity’s basest urges, and you’ll worry about “The Future,” too.

But “Jeopardy!,” one might argue, is the best of America. We are not hysterical for new cars (like the boobs on “The Price Is Right”) or clapping incessantly at a glittering disc (like the spinners on “Wheel of Fortune”). Nor are we hoarders, or addicts, or teenaged and pregnant. We are brainy citizens — copywriters, systems engineers, elementary school teachers — who excel on national television.

An average of 9.1 million viewers watch “Jeopardy!” every day, a bit fewer than “Wheel of Fortune”, plenty more than “Who Wants to be a Millionaire?” In the D.C. area, “Jeopardy!” out-performs “Wheel,” which is technically America’s No. 1 game show, and this month achieved double the household rating of its time slot competitors “Access Hollywood” and “Entertainment Tonight.” A smarty-pants town loves a smarty-pants show, and many contestants spring from the capital region, says Andy Gefen, a financial consultant who lives in Bethesda and administers JBoard.tv, an online convocation for super fans to discuss study tips, wagering strategies and “Jeopardy!” Pavlovs (facts that recur in clues through the seasons).

“I check their Web site to see who the contestants are going to be, and it’s almost always someone from the D.C. area or the Baltimore area,” says Gefen, 54, whose appearance on the show aired in January 2006 (he placed second) and who sometimes joins other former contestants for bar trivia nights in Maryland. “They clearly draw a lot of contestants from California, because it’s a lot easier to recruit them, but I think Washington pops up probably even more than the New York area.”

Viewers enjoy pitting themselves against players who’ve passed the show’s rigorous application and audition process, says Robert Knecht Schmidt, a patent agent and law school student in Cleveland who started the J! Archive, an online database of every game board, contestant and result since Trebek’s first show in ’84.

“Trivia is representative of the culture,” says Schmidt, 31, who appeared on two episodes in 2010. “The show has changed — it’s gotten more punny and it has relied a lot more on Pavlovian associations — but it’s still hard.”

The studio set and the Final Jeopardy jingle have gone through numerous redesigns and rearrangements without really changing the show at all. The show doubled its dollar amounts and added the Clue Crew in 2001, removed its five-show winning-streak restriction in 2003, drew new obsessives during superchampion Ken Jennings’s 74-win romp in 2004, and gained fresh publicity by pitting an IBM supercomputer against past champions.

Has Trebek changed (and not changed), too? There are viewers who are captivated by his impassivity, or incensed by his pronunciation of foreign phrases, or worshipful of his contained authority. In the ’90s, Will Ferrell routinely portrayed him on “Saturday Night Live” as a stolid, semi-pompous suit who can barely hide his contempt for brainless celebrities.

Trebek thinks he’s softened over the years, abandoned his aloofness, become more sympathetic to contestants. Friends are telling him to go for 30 seasons, at least. Regis Philbin went for 28. Bob Barker went for 35. Pat Sajak, with whom Trebek shared a lifetime achievement Emmy last year, is completing his 29th. When retirement comes, Trebek says, it will come naturally, and then he will travel and read more. He’ll renew his lucrative contract year by year until he doesn’t. The job will be satisfying until it isn’t.

The show “allows you to benefit from all of this stuff that you have learned in your life that you would never have been able to put to good use otherwise,” Trebek says, although it’s “not so much about rewarding knowledge as it is trying to instill a love of learning, a curiosity about life, about everything.”

‘A quest for knowledge’

And now a final break in taping at Constitution Hall, to approximate commercials for auto insurance and prescription sleep aids. Trebek is taking questions from the audience again.

“Do you have pets?”

He used to have two dogs, he says, but one died and the other was dragged off by a California coyote.

“Have you ever been invited onto ‘Dancing With the Stars’?”

Yes, he says, but he declined because of his 2007 heart attack, several operations on his back and his shriveled ACL. Plus his knee has ground its own cartilage to dust.

Trebek in person is not just a host, the hollow vessel for a cultural entity, but a regular guy with joint pain and a sweet tooth.

The show runs like clockwork. As it should. It’s been the same for generations. As has Trebek’s job, though his mind seems more adrift. Or free. Free enough to realize that even though he’s been lodged behind a lectern for 28 years, with all the questions in front of him, he’ll know neither his true place in the cosmos nor the answers to everything.

“I don’t think we ever figure it out,” Trebek says. “Some people can tell you, ‘Oh, I figured it out.’ Oh yeah? Good for you. But my life has been a quest for knowledge and understanding and I am nowhere near having achieved that. And it doesn’t bother me in the least. I will die without having come up with the answers to many things in life.”

So he creates, on a soundstage, a safe Trebekian world where everyone is competitive but kind, where the only politics is a category of honest-to-goodness facts, where we pursue knowledge for the sake of knowledge, where he keeps America off thin ice, at least for 30 minutes every weekday night.