The Stranger Favor: A Happiness Boost That Lasts All Day

At a store the other morning, I went to pay for four bagels and realized that I couldn't. "Oh, I left my wallet at home!" I told the cashier, more disturbed that I'd be denied my bagel fix than by the fact that I'd been driving around without a license.

"I can pay for them!" said the woman next to me. I turned to look at her. "Really? That's so nice of you," I said, genuinely surprised. "No big deal!" she responded, cheerfully, and paid for my bagels along with hers. I thanked her profusely. For the rest of the day, I had the warm-fuzzies: Her $3 gesture had reaffirmed my faith in the goodness of humanity.

It always amazes me how happy-making it is when strangers do you a favor, whether it's a pedestrian taking time to point out that your purse is open or a fellow customer letting you skip the checkout line when you only have one item. Heck, just reading about this stuff gives you a lift. One impressive recent story: a stranger at a Provo, Utah, bridal store bought a woman a $480 wedding dress.

That Random Acts of Kindness movement has been around for decades now, propelling people to do things like feed change to a parking meter that's expired or pay for a stranger's coffee at Starbucks. More recently, there's been the #FeedtheDeed social media campaign, inspiring people to pay it forward and then nominate friends to do so. I find the old-fashioned "Take time be nice, people!" message heartening and inspiring, given the rushed, high-tech ways of the world (though I can live without suggestions like "Say 'Bless You' When Someone Sneezes" that assume we were all raised by wolves).

There are definite self-serving reasons to do good: Kindness is a bliss booster. As University of California professor Sonja Lyubomirsky, PhD, notes in Health's recent story 14 Strategies to Become a Happier Person, "I've found that when people are told to try to do three to five acts of kindness a week, they get happier." In one study in The Journal of Social Psychology, researchers asked participants take a survey on life satisfaction, then divided them into three groups. One group had to do a daily act of kindness, another was told to just do something new every day, and a third group got no instructions. After 10 days, when participants again took the satisfaction survey, the groups that had practiced kindness and did something novel had a notable rise in happiness.

"When you're doing good deeds, you're enticing a common feeling across two people, and that's part of what knits a community together," social psychologist Barbara Fredrickson, PhD, told U.S. News & World Report in 2013. Plus, she continues, "You're on this path to be a better version of yourself." It may even improve your heart health: in one study in Psychological Science, people who learned meditation that nurtured feelings of love, compassion, and goodwill toward themselves and others felt more socially connected than the group that hadn't done the meditation—and had improvements in vagal nerve activity, which regulates heart rate and has been linked to cardiovascular health.

So by all means, let someone who looks rushed cut you on line. Tweet or post a compliment. My own weekly random act of goodness is to leave magazines I've read on top of the recycling bin at the train station, so others can enjoy them. Just don't forget one of the kindest gestures of all: Helping someone head off severe mortification, and I'm not just talking about a spinach-in-teeth situation. I was at an event with my husband a couple of months ago, and took a bathroom break. Maybe 10 minutes later, a woman walked over to where I was standing and whispered in my ear "The back of your skirt is tucked into your tights." I was grateful to have a faux pas guardian angel—except I couldn't stop wondering why other people there hadn't said a peep.