All lasting friendships have this one thing in common

USA: WHAT’s the secret to a longlasting friendship? There are lots of things you can point to—common interests, similar personalities, shared experiences. But there’s one thing that no long-term friendship can ever be without: boundaries.

Just like a relationship with a romantic partner or a family member, boundaries in friendship generate mutual respect and empathy. Read on to learn more about how boundaries keep a friendship healthy and lasting.

What Are Boundaries?

When you set a boundary in a relationship, you are expressing to the other person what you need from them and how you need to be treated.

1 Setting a boundary might involve telling the person if a certain action of theirs makes you uncomfortable, or if a specific topic of conversation is off-limits. You might also need to explain how you’d like to be treated under certain circumstances, like if work is really busy or you’re not feeling well.

“For example, ‘Please do not call me after 9 p.m.’ is not technically a boundary but a request. ‘If you call after 9 p.m. I will not answer, and you will get a response when I am available’ is a boundary. You choose how you will respond if the boundary is not kept, and know that if you do not respect people’s boundaries they might not allow ongoing access to them,” adds Dr. Marschall.

It’s also important to be aware and respectful of the other person’s boundaries yourself. If someone is taking the trouble to outline what they need from you in terms of your behavior towards them or the way you speak to them, listen.

“Boundaries are so important!” says Dr. Marschall. “They are how we let people know what we need in order to be in a relationship with them. You are allowed to set boundaries around what you need in your relationship, and if you care for and respect someone, you will honor the boundaries they set for you. If you do not honor someone’s boundaries,” Dr. Marschall advises, “they might not allow you to remain in their life.”

Boundaries in Action

I was having lunch with a friend a few months ago and we were talking about a mutual acquaintance we had both (separately) spent time with recently. I told my friend I had repeated something she’d said about this acquaintance to him because I thought what she said was funny and knew he would appreciate the joke. My friend laughed when I told her this, and we moved on.

However, after lunch, I received a text from my friend. She told me that it had actually made her really uncomfortable to know that I had repeated something she’d said to this other person without her permission. She asked me very plainly to not do this in the future, and to always ask her first before telling others about anything she has said.

I was horrified. I immediately understood my mistake and assured her this would never happen again. I also apologized and told her that she deserved to have a friend she could trust and that I recognized that I had violated her trust.

This is a prime example of how boundaries should work in a friendship. My friend (of nearly 15 years, by the way) was able to speak up for herself and express to me what she needed from me, and I was able to acknowledge how I had not respected those boundaries and the importance of doing so in the future.

If this exchange had not occurred, this most certainly would have affected our friendship. My friend would have continued to feel as though I had hurt her, and I would have had no idea what I had done wrong, and therefore would not have been able to adjust my behavior in the future. Speaking up and reinforcing those boundaries was the best thing she could have done in this situation.

All this to say, setting boundaries will do wonders for your friendships. And eventually, this will become old hat—you learn where your friends’ boundaries are and they learn yours, and your relationship can continue with respect and empathy.

What it looks like when boundaries are not respected

My friend, who had a surgery scheduled, asked  me a few weeks in advance if I would pick her up from the hospital afterward, and I agreed. However, a few days before the surgery, I had to make a difficult decision regarding my own health, which meant telling my friend that I might not be able to pick her up after all— I didn’t want to commit to helping her when I wasn’t absolutely sure that I would be up to it on the day, therefore leaving her in the lurch.

I felt terrible for letting her down, but I had hoped that my friend, who had similar health issues, would understand that I needed to take care of myself during this time; but she didn’t.

She said I was selfish, told me I was a horrible person, and said that she would never forgive me, even though I apologized and tried to explain how hard this decision was for me. She called me multiple times to scream at me, to the point where I stopped taking her calls; after that came a barrage of vitriolic text messages until I eventually had to block her.

I would have understood if she had told me she was disappointed in me, and that I had made things more difficult for her because both of those things were true. But the fact that there was no consideration for my situation and the way I was feeling made it very clear that this friendship was not going to continue much further—and it didn’t.

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I asked her to understand my position and what I needed at the time, even though it inconvenienced her, and she couldn’t. Knowing that someone cannot respect your boundaries, especially when health is on the line, makes it difficult to continue being friends with that person.