What Science Reveals About Female Friendship

After going away for a long-awaited 50th birthday celebration with my best friends from college, I came home happy — and annoyed at the same time. While it was great to see everyone, one of my girlfriends seemed to spend the entire time on her phone. I couldn’t understand why she would travel thousands of miles to come to New Orleans with her friends, only to seem distracted by whatever she was watching on YouTube or reading on Facebook. I decided then and there to let our friendship drift apart, so I stopped calling her.

Although I love my friends dearly, sadly it wasn’t the first time I’d had an issue with a girlfriend. I found that, sometimes, my friends could behave in strange and mysterious ways — they would act jealous or unfeeling toward me, or even try to undermine me.

What makes women act this way? As I started talking to my current friends about my experience, I realized that I wasn’t alone. Many of them had their own story about the friend who “got away,” and were still sad about the loss.

Friends are so important to women, and studies have shown that a breakup with a friend can feel even worse than a divorce. But what really struck me when I talked to my friends about their girlfriend breakups, besides the grief, was the sense of confusion. None of us could figure out what had caused a close friendship to turn sour, and that made me curious about the mystery behind these rifts.

I wondered if there could be a scientific explanation for women’s behavior toward their friends, both good and bad. If I could find the key to how female friendship worked, could I learn to avoid my own relationships falling apart?

One of the biggest insights that I discovered from researching my book,  Girl Talk: What Science Can Tell Us About Female Friendship, is that the complex and even perplexing nature of women’s behavior can be traced back to human evolution.

For instance, in many traditional societies throughout history, once a woman found a mate or husband, she typically left her family group and went to live with him and his family. Because women had to live with and get along with strangers, they invested in fewer relationships and had smaller social groups. Yet they devoted themselves highly to these friends so that they could enjoy a more secure social network while living with their mate's family.

The unique ways that women communicate today, such as talking about their intimate lives and crying in front of their friends, are a result of these smaller friend networks. By disclosing vulnerable information to their close friends, they’re able to build trust — and they're better able to hold on to this smaller circle of friends.

As a result, women’s friendships tend to be more intense than men’s — but also more fragile. Since it’s so important for women to rely on each other, they don’t tolerate breaches of trust well, and little things that may seem trivial, such as not turning up when you’re invited somewhere, can tip things over the edge.

And that’s when friendship breakups can happen.

While I was doing research for my book, I read something else that resonated with me: It’s easy to walk away from problem friendships — but by working through conflict when things go wrong, we have the potential to create deeper, more meaningful friendships.

So instead of ignoring the problem with my college friend, I decided to tell her how I felt. It wasn’t easy, but after being friends for so many years, I knew the relationship was worth saving. It turned out she hadn’t realized that I’d been bothered by her behavior, and she apologized, promising to change. She also told me that she had a health issue she was dealing with, and that it had made her anxious about the visit, worried my friends and I would be asking her questions about something she wasn’t ready to talk about. I hadn’t known this — and it helped me to understand her behavior.

Although we don’t see each other or talk as much as I’d like, I still consider her one of my closest friends.

Now, I take it less personally when female friends act strangely with me, because I know that their actions are rooted in the evolution of human behavior. And that, while painful, these occasional breakups are the evolutionary flip side of the warmth, satisfaction and sustenance that my friendship with my girlfriends brings me.