The signs of happiness are right in front of you. You’ll see them as you drive into the city on a Monday morning, steeling yourself against another day in front of a computer screen.

We’re talking about four poster-board signs held by four relentlessly optimistic people, a sort of pep squad for the beleaguered office drone. The signs on this day read: “Honk if you love someone!”; “Be happy”; “Don’t be so hard on yourself”; and, of course, “Smile!”

The signs are the work of Massoud Adibpour, 29, of Columbia Heights. He and friends have spent the past four Monday mornings holding them up in front of rush-hour traffic, to a cacophony of honks. They stood on the Mall at 14th Street, the best place to catch commuters coming across the bridge from Virginia to begin another bleary-eyed Monday. Passing bicyclists dinged their cheerful bells. Pedestrians gave a thumbs-up. Unmarked cop cars blew their cover by flashing their lights. Drivers of 18-wheelers yanked on their air horns, loud enough for a tugboat. Most people smiled.

With his signs, and without knowing it, Adibpour has engineered what psychologists in the science of happiness call a “positive intervention.”

Yes, there’s a science to happiness, and it has its own math: For each negative encounter in a day, people need five positive interventions to keep up their happiness quotient, says Caroline Adams Miller, an executive coach and author of “Creating Your Best Life.”

But for that dynamic to work, people have to respond positively to the intervention. “It is a voluntary behavior or thought change that takes you from either negative to neutral, or neutral to positive, or positive to even more positive,” Miller said. In other words, scowl at Adibpour and his sign-toting friends and you’ll have to put up with the rest of your miserable day.

And even though the group’s signs provide only a brief moment of cheer, people shouldn’t write off the good effects, Miller said. A sign that jogs feelings of gratitude or contentment triggers a mind-set that will encourage good feelings throughout the day.

“Those fleeting moments . . . add up throughout the day to generate other positive emotions and offset the negative ones,” Miller said.

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Since February, Adibpour has been plastering signs around the District, mostly in Columbia Heights, Adams Morgan and the most ulcerative of all areas, K Street. They’re all encouraging, scrawled in his quirky hand-lettering — e.g., “Life is short. Take chances.” Some are interactive, like the sign that reads, “Take what you need” with little tear-away strips of paper that say “love” and “luck.”

Adibpour’s sign offering love and luck already has caused a ripple effect of happiness. After seeing the sign in Columbia Heights, former neighborhood resident Sophie Miller constructed a giant chalkboard with the prompt “Before I Die . . .” to encouraged passersby to fill in their bucket-list hopes and dreams.

Happy minds must think alike. Last Monday afternoon, Adibpour set up a table at the Columbia Heights Metro stop with bucket-list sheets and invited commuters to jot down their goals and desires. Responses included “Cure HIV,” “Be a celebrity make-up artist” and “Meet my dad.”

Adibpour has his own 100-item bucket list, to be completed by May 29, 2032. “Having a physical copy is important,” he, pulling the water-stained list out of his wallet.

Some of his goals, which also are listed on his blog: Crash a wedding, travel to North Korea, visit family in Iran and see Daft Punk in concert.

But Caroline Adams Miller points out that bucket lists aren’t just fodder for a Jack Nicholson/Morgan Freeman buddy flick. Life-goal setting is directly correlated with happiness, she says.

“Proactive people who lead forward-looking lives, who are connected to other people, giving back and going out of their comfort zone are the . . . things you find when you study happy people,” Miller said. “They don’t live lives of ease; they have a certain amount of grit.”

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