Even though we never did anything outside of work, some of my co-workers and I were fairly close. We talked. Commiserated. Occasionally confided. All the hours we spent together, and the shared experiences that resulted, made me think of some as close friends. 

Until the day I resigned/got fired. (As Star-Lord of Guardians of the Galaxy might say, "Bit of both.") 

Then I realized that, except for one, they were work friends. Not friend friends. 

Hold that thought. 

According to a multigenerational Harvard study that Inc. colleague Bill Murphy Jr. has done a lot to make famous, friends can make a huge difference on happiness. Researchers spent decades years studying three generations of people. What did they find?

"The clearest message," says Robert J. Waldinger, the current head of the study, "that we get from this (then) 75-year study is this: Good relationships keep us happier and healthier. Period." 

Keep Your Friends Closer

But with a twist. Proximity matters:

  • If you're surrounded by many happy people who are "central in the network" (meaning close friends), you're more likely to become happy in the future. But ...
  • A friend who lives within a mile and who becomes happy increases the probability that you will be happy by 25 percent. And ...
  • The farther away the friend lives, and the more that time passes during which they live farther away, the less happy you will be as a result of their happiness.

Add it all up, and here's the lesson: Happiness is directly related to friend relationships. And how close you live to your friends.

The effect is more dramatic than proximity to family: Compared with the happiness of a sibling, the happiness of a friend who lives within a mile of you is approximately 1.5 times more likely to improve your happiness.

But Maybe Not Your Work Friends

Unfortunately, though, even though you (at least used to) spend considerable time in close proximity to your work friends every day, the happiness of work friends won't make you happier.

As the researchers write:

All these relations indicate the importance of physical proximity, and the strong influence of neighbors suggests that the spread of happiness might depend more on frequent social contact than deep social connections.

On the other hand, we found no effect of the happiness of co-workers, suggesting that the social context might moderate the flow of happiness from one person to another.

In short, work friends are still just work friends.

And deep inside, you know it. According to research conducted by the Health Resources and Services Administration:

  • 40 percent of Americans say they "sometimes or always feel their social relationships are not meaningful,"
  • 20 percent say they are "lonely or socially isolated," and
  • 28 percent of older adults live alone.

That matches up with a 2018 study conducted by Cigna that found only half of Americans say they have "meaningful" in-person social interactions on a daily basis. (That was even truer for people born in the late 1990s.)

And that's before the coronavirus pandemic likely decreased the chances for meaningful in-person interactions.

Make Your Close Friends Happier. You'll Be Happier, Too

Hard-working people like to associate with hard-working people. Fit people like to associate with fit people. Successful people like to associate with successful people.

Happy people like to associate with happy people.

But the effect isn't just correlated. The research shows it's also causal. When a close friend is happier, you feel happier.

So make it a win-win. Help a close friend feel happier. Do something kind. Say something kind. Volunteer to help, without being asked. Don't expect them to make you happier. Help them feel happier. 

Not only will you enjoy seeing them feel happier, since giving is often just as fulfilling for the giver as for the recipient, but science says their happiness will actually make you happier as well. 

Bottom line? Go ahead and keep your work friends close.

But keep your friend friends closer.

And as happy as they can be.