Kevin Sun


Four metrics for friendship

Why do different friendships feel different?

October 24, 2019

"Evaluating" a friendship sounds cold and robotic, but I think it helps us answer a few interesting questions. What are the necessary conditions for friendship? Are there any sufficient conditions? Can you be friends with a coworker or an ex? What does it even mean to be "friends"?

This post isn't a guide on how to make friends. Instead, it's a way to evaluate existing friendships and the features that make them work. The term "friend" is very broad, so having a set of metrics adds quantitative structure to our social network. As we will see, the outcome is a four-dimensional vector representation of every friendship. (Again, cold and robotic, but hopefully interesting.)

By performing this analysis, we can start to answer questions about our friendships and even discover insights about ourselves. Why am I friends with X? How come my two friends, X and Y, don't like each other? How come Z and I are merely acquaintances, even though we seem to get along quite well?

To address these questions, I shall propose four metrics. To evaluate a friendship, you simply consider how high it scores in each of the metrics. Before stating these metrics, let's keep a couple of things in mind:

Now we finally state the four metrics. Generally, the more X a friendship has, where X is any metrics listed below, the stronger I perceive that friendship to be. A perfect (10, 10, 10, 10) friendship probably doesn't exist.

  1. Flow: Do they pay attention to you when you talk? Do you enjoy listening to what they have to say, even if you wouldn't otherwise care about the topic? How often do you stop yourself from saying something that you'd probably say to another friend?

    Note that two friends do not necessarily have to talk an equal amount. Some people enjoy talking more than others, and if they meet someone who enjoys listening to them, the result can be a pleasant yin-yang situation. But generally, an open channel of communication, in both directions, is critical.

  2. Humor: How often do you laugh together? Are you comfortable to laugh at each other sometimes? When you witness an absurd or awkward event, do you look forward to telling them about it?

    Sometimes, humor comes in prepackaged bits; for example, fans of The Office might frequently reference moments from the show together. The humor can also be somewhat dark — friends who are suffering through a difficult experience together might laugh at their shared misery. Close friends can even poke fun at each other's insecurities.

  3. Utility: It sounds kind of icky to ask how "useful" a friend is to you, but I think a good friendship should contain some utilitarian value. Have they ever helped you with a homework assignment? Would you ask them for a ride to the airport? Would you help each other move, or assemble furniture?

    A relationship rarely survives off utility alone — once the transaction period (e.g., a school semester) is over, the relationship often ends as well. But the best friendships often yield the highest "returns." For example, a friend might take care of your pets while you're on vacation, or invite you to sleep in their guest room whenever you're in town. Maybe they'll even agree to be a godparent of your child.

  4. Intimacy: This refers to the general feeling of being close with someone (not necessarily in a romantic way). Are you willing to share embarrassing stories or insecurities with them? Or maybe discuss a recent dispute with a mutual friend? Would you tell them about your relationship or family issues?

    It's possible to be intimate with someone in certain areas (e.g., career insecurities) but not others (e.g., political views). Some people view sexual activities as highly intimate, while others do not. In my experience, it's hard to find someone with whom you can share every aspect of your life — those friendships are rare.

It's hard to say whether a (4, 9, 4, 6) is "better" than a (6, 5, 6, 6). Maybe you prefer playing video games with friend A while discussing politics with friend B. Anyway, hopefully these metrics give some structure to thinking about the nature of your friendships.