You probably have a number of work friends with whom you laugh. Commiserate. Confide. Because of proximity and shared experiences, you might even consider a few work friends among your closest friends.

Great--but don't expect your work friends to make you feel happier.

According to a famous multigenerational Harvard study on happiness, one that tracked three generations of residents and their offspring to discover trends in the way that happiness moves among a population:

  • Individual happiness extends up to three degrees of separation (for example, to the friends of one's friends' friends).
  • People who are surrounded by many happy people and those who are central in the network are more likely to become happy in the future.
  • A friend who lives within a mile and who becomes happy increases the probability that a person is happy by 25 percent.
  • The effect decays with time and with geographical separation. 

In short, happiness is directly related to relationships--and more importantly, the proximity to the people with whom you share those relationships. 

Here's the proximity breakdown, ranked by greatest effect on happiness to least:

  1. Nearby friends (a person the respondent names as a friend, and that person feels the same way)
  2. Next-door neighbor
  3. Nearby "my-way" friend (I think of her as a friend, but she doesn't think of me as one)
  4. Nearby their-way friend (I don't think of her as a friend, but she thinks of me as one)
  5. Nearby sibling
  6. Co-resident spouse (seems weird that your spouse ranks sixth, especially since your spouse has a dramatic effect on your job satisfaction and success)
  7. Distant sibling
  8. Distant friend (one who, no matter how close you may feel emotionally, lives over a mile away)

While blood is thicker than water, distance matters even more: The happiness of a nearby friend--one living within a mile of you--carries a nearly 150 percent probability of improving your happiness, while nearby siblings carry significantly lower impact.

And so do your "close" friends, especially when they live further away.

Work Friends Don't Count

The main takeaway: Distant friends are fine, but the closer your friends are to where you live, the better.

But that doesn't include work friends, even though they "live" alongside you for much of the day. 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 [my bold]...suggesting that the social context might moderate the flow of happiness from one person to another.

Or in non-researcher-speak, no matter how close you might feel to a work friend, deep know you're still just work friends.

Make Close "Close" Friends

"Clusters of happiness" don't just occur because happy people tend to associate with happy people. The effect is causal, not just correlated.

To feel happier, make close "close" friends. Or improve your relationships with a few nearby friends. 

But don't expect them to make you happy. They need to be happier first, because when they are...that's when you feel happier. Think about what you can do that will help the people closest to you be happier--and then do it.

See "care" as a verb. Step in. Step up. Step outside of yourself and do something selfless, just because you can. 

The happier your friends are, the happier you will be.

And their happiness is at least partly within your control.

Especially if you choose for it to be.