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They're That Person Smiling at Strangers

Their secret: Interacting with people they come across throughout their day—whether it's the woman in front of them in line at their favorite lunch spot, the barista at the local coffee shop or the stranger standing next to them waiting for the light to change.
Why it works: All three experts we spoke to for this story said that strong relationships are one of the single biggest predictors of happiness. But short, simple encounters—even if they're with someone you may not see again—make you feel connected to the broader community around you, which also increases your joy, says Christine Carter, PhD, sociologist and a senior fellow at UC Berkeley's Greater Good Science Center and the author of The Sweet Spot: How to Find Your Groove at Home and Work. "If you're walking around town and looking at your phone at every stoplight instead of acknowledging the people around you, and everybody else is doing the same thing, you'll feel isolated even though you're surrounded by people," she says. "All you have to do is look up."

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