You probably don't need science to tell you this, but if you need hard data, research proves that friends are one of the most powerful happiness boosters out there. Not only do strong relationships help you live a longer, more joyful life, but meeting up with friends has been shown to be one of the most powerful stress busters.

The trouble is, once you get out of the social bubble of school, making close friends gets harder. And finding a new social circle is even more difficult if you've been forced to relocate away from old ties. So what's the best way to build strong friendships in the more atomized adult world? Science has a quirky suggestion for you.

People who move together, bond together

The idea comes from an interview with Robin Dunbar, an evolutionary psychologist who studies friendship at the University of Oxford, that appeared recently in Scientific American.

The long article is full of interesting tidbits about how the human brain is wired in regards to relationships, and is well worth a read in full, but if you're simply in the market for a bit of actionable advice on how to make friends, here's Dunbar's unexpected but research-backed idea:

One of the best ways is joining a singing club. We did a study comparing novice singing classes with novice hobby classes in terms of how much these activities produced feelings of social bonding. Singing produces a massive hit of endorphins, and that makes you feel very bonded to the people with whom you're doing it. We call it the "icebreaker effect." It seems when you go once a week to your glee club or barber's quartet and sing together, it just ramps up this sense of belonging.

It's similar with dancing and jogging. I see people jogging with their earbuds, listening to music, and I think, "You're doing it wrong. Take the freaking earpieces out and talk to the guy next to you." It'll ramp up the effect of the workout or the dance. You're going to get an endorphin kick from any physical activity, but if it's done in synchronicity with somebody else, the effect ramps up significantly, our studies of dancers and rowers have found. And that's why dancing works, too--you can have large numbers of people doing the exact same thing in sync.

Sing, dance, and cry your way to greater health?

Activities that require you to move in sync with others apparently help you feel in sync with them too. That's great to know if you're the new person in town (or looking to bond with your attractive date), but this principle does more than simply help people build stronger personal connections, Dunbar adds.

Finding ways to sing, dance, and move with your fellow humans isn't just good for the soul. It's even good for the body too. Your "network seems to cushion you... the endorphins that kick in from interacting with them seem to tune up your immune system," Dunbar explains.

"Laughing together, jogging together, dancing together, singing together, telling emotionally wrenching stories, going to see weepy films--these activities buffer the body biochemically and immunologically against the kinds of coughs and colds of everyday life," she concludes.

So next time you're wondering what to do on Friday night, keep this research in mind. It might not only help you make a new friend and be happier, but dodge the flu too.