The Secret Science Of BFFs

About two years ago I was a reformed backpacker moving to New York to try to break into journalism. Somehow I got an intern gig at cool business magazine. It was in a skyscraper. I had no idea what I was doing.

On my second day, a guy named Dan (I forgot his name a few times) drew me a map of the office: my editor was here, her editor was there, and oh yeah, I sat with the other interns.

We started having lunch together. We learned that we had both lived in South Korea after college, started ultimate Frisbee teams in high school, played Magic: the Gathering in middle school.

We also a learned that I hadn’t cut my hair in two years and Dan flossed multiple times every day. He had mated for life; I was still carousing. He was decisive, I was ponderous.

It was an odd couple. It was guy love. It was best friends for life.

The science of BFFs

Friends improve our memory. People with close friends live longer. Our ability to make friends in middle school predicts how successful we’ll be in life. Thing is, the importance of BFF-ship goes back lots of years. Like, evolution numbers of years.

1. Having a BFF increases chances of survival.

“When we lived in groups where survival itself was difficult, you needed someone who would be guaranteed to throw you a lifeline,” Carlin Flora, the author of Friendfluence: The Surprising Ways Friends Make Us Who We Are. “You can easily theorize that the notion of a best friend developed because we needed someone where we were number one on their list and they were number one on our list in those life and death situations.”

In other words, if a mammoth were to threaten our encampment, Dan would be there with me to spear that fucker down. Plus evolutionary psychologists make a parallel argument for female-female friendships: in our intensely gendered prehistory, ladies would select friends who could help with the kids–co-parenting, if you would.

This is also why, Flora explains, girls go so ape when their girlfriends get married. If the bride doesn’t pick you as the maid of honor—or doesn’t even put you in the wedding party—that means that you’re not at the top of her survive list. Which, back in those mammoth days, could mean a lot worse than pouting on the wedding day.

2. BFFs provide respite from more complex relationships, such as familial ones

But when they’re not getting married, research suggests that we’re actually at our happiest when we’re with our friends. Daniel Kahneman, who won a Nobel Prize for economics even though he’s a psychologist, did a study to help us learn why. For many days, throughout the day, subjects answered a short survey asking how they felt right then, what they were doing, who they were with. The results were surprising: people were happiest not when with lovers, family, or kids, but with their friends.

Is this because everybody hates their families? Not quite. As Flora, the author, explains, our friendships aren’t “fraught” in the same way that our relationships with our dads or girlfriends are: there’s logistics to be sorted through and baggage to be released. Friends are our “respite,” Flora says, and better we spend time with our friends, the more energy we’ll have to be the perfect girlfriend or boyfriend.

“Think of the expectations you put upon a partner: since you only have one partner, you expect them to fill a lot of needs,” she says. “But you can have several friends, you don’t expect any one friend to be everything to you.”

3. Our brains treat BFFs as extensions of ourselves

Brain scans show that we get the same fight-or-flight threat response in our brains when we see our friends in danger as if that mammoth was coming right for us. In other words, our brains literally treat our BFFs as extensions of ourselves.

Maybe that’s why we act so much like our friends. Harvard Medical School professors have found that behaviors move like diseases—you’ll catch the bug of quitting smoking, getting fat, or being more happy from your friends like you would the flu. Maybe that’s why Dan’s meditating every day. And I’m flossing every day. And we’re still playing Magic.

4. Being a good BFF means making them feel like they matter

After learning about all these ways that friends make our lives better, Flora happened upon a few keys for being a more excellent friend. We should be giving them the benefit of the doubt, accepting that they’ll bore, frustrate, or disappoint us, and more giving to them.

Which, weirdly enough, means asking.

“The less obvious lesson would be to ask friends for favors,” she says. “One of the main reason friends make us happy is they make us feel like we matter. They make us feel needed. That means if you never ask your friends for favors, they don’t get that satisfaction of feeling needed by you. It feels pleasurable to give, to feel like, ‘I matter to this person, I get to help them.’”