A chance meeting set Kelly Valen thinking about how she had been bullied by her sorority sisters at college. But the resulting newspaper column and book have caused a storm

ASK MOST women and they will tell you that at some point in their life another woman broke their heart. Not romantically but when a close friendship fell apart. Some of the reasons are understandable – distance, hectic lives, growing apart – but the fallout can be devastating. Kelly Valen's new book, The Twisted Sisterhood: Unraveling the Dark Legacy of Female Friendships, looks at reasons that are less easy to comprehend: when friendships falter because of insecurity, jealousy and more than a touch of Schadenfreude.

The book was born out of a 2007 article Valen wrote for the New York Times,triggered by a chance encounter with "a sorority ghost", a woman who had been cruel to her at school.

“I was at home one day and realised that the encounter had really consumed me and brought back a lot of bad feeling, so I put it all down on paper. It was probably the easiest thing I’d ever written. Within 24 hours the response had been huge,” she says.

Hundreds of women left comments and sent e-mails to say how much the piece about the toxicity of some female friendships had resonated with them. Not everyone agreed, however, and Valen was accused of everything from betraying her gender to stabbing the sisterhood in the back.

"I never set out to write this book. I wrote this essay and wasn't even sure about publishing it. I still remember my finger hovering over the 'send' button before I sent it to the New York Times. Most of the e-mails were very supportive. The ugly stuff was a small part of it, but it was very vocal and in the blogosphere. There were all these misunderstandings and strange assumptions about me, and I couldn't understand how it insulted people.

“Nowadays I’m not that naive, and these are inherently emotional issues. The book is very pro-woman, but we have to get over the hurdle of being able to look at our flaws.”

The feminist website Jezebel was critical of the article, asserting that Valen’s “hatred” of women was rooted in a date-rape episode at college, when she was ostracised by her sorority. Since the book’s publication Valen has been made well aware of the unpopularity of her subject and feels people don’t like the hive she’s poking at.

For The Twisted Sisterhoodshe surveyed more than 3,000 women about their friendships with other woman. Despite the huge amount of feedback from readers, high-profile support has been hard to come by.

“I wrote for the Huffington Post and appeared on Oprah’s radio show and in her magazine, but, on the whole, well-known women have been cautious about endorsing this book because it makes people uncomfortable. It’s also very interesting to me that some of the big feminist websites have been so quiet about it.”

Given the divisiveness of the issue, some have steered clear of the book, taking the view that she has generalised women and painted a stereotype of bitchy, cat-fighting frenemies.

“You really need a thick skin to write a book about women. Some women have gotten upset with the book before they’ve even read it. They’ve assumed that I’m beating up on women, and I don’t want to be viewed as some sort of female misogynist.”

Speaking to Valen, it’s clear that she’s not, and much of what she says is based on reportage and survey rather than random theorising. Male friendships also feature clashes of ego and competitiveness, however: are the issues she raises in the book specific to gender?

“Men are clearly not the primary audience of the book. A lot of people say to me, ‘Men do this too; you’re giving them a free pass,’ but that’s not what the book is about.”

A lot of the behaviour she examines in The Twisted Sisterhooddeals with friendships that falter over issues of conflict and jealousy. She cites numerous interviews that are sad records of broken friendships, of women who had a best friend turn on them, motivated by feelings of inadequacy. A once-bonded connection unravels – and, with it, a long-term friendship.

“Whatever your perspective, whether you think this behaviour has an evolutionary basis or that it’s our male-dominated society that’s causing us to do this to each other, most people agree it’s our insecurities that are driving it.

“If you’re secure in yourself, you’ll be less vulnerable to falling into this game-playing, and more resilient if it does happen. That’s why I think it’s so important to grow confidence in our young girls.”

Valen, a mother of four, has three daughters, including 10-year-old twins. They were part of the motivation for this project. “All of this unnecessary negativity around us really bothered me. No one had written that next chapter about the effect it was having on people. It’s not just harmless: there is fallout from this behaviour.”

That fallout affected a friend’s daughter who, having been bullied on Facebook, killed herself. “It really hit me,” says Valen. “Like in the Phoebe Prince case, these girls probably had no idea that their harassment was having such an impact.”

Several of the stories in the book relate to growing up in a pre-internet world, and Valen is very aware of how technology has caused a proliferation in what she terms “mean-girling”. “Aggression with women is more subtle. It’s not that kind of physical conflict that men have, so something like the internet can exacerbate it. There’s bullying on Facebook, Twitter, on forums. Any time you put yourself out there on the internet it’s going to be negative. There’s so much gratuitous negativity flowing from other women.”

Many of the experiences told to Valen relate back to schooldays and summer camps. What comes across strongly is not just the hurt of youthful bad experiences but the damaging long-term effects for some.

“Even the most fully adjusted among us never forget painful run-ins with other women. Some feel it’s a reason why they avoid book clubs and yoga classes; why they don’t feel comfortable in groups or with certain kinds of women. Memory is very strong, and they link their feelings back to their past. When group think rears its head, it can be an ugly thing.”

Valen interviewed women from all walks of life, and a small minority admitted they never had issues with other women. The stories often surprised the author. “One woman who was a professor and published poet told me that reading her poem at a Yale book store was one of the proudest moment of her life. The poem was about a summer-camp experience where other girls bullied and excluded her. She was such an accomplished woman who had achieved so much, and yet the experience had coloured her attitude to other girls and women for life.”

She says we learn acceptance with age. Things that once bothered us no longer do. Valen herself has dealt with many of her own demons. “Every woman is different, but most of us get more comfortable with age . . . Things bother us less. We choose more wisely with our friendships, and we learn to weed out the toxic people.”

As a mother, does she believe it is possible to teach children to avoid unpleasant behaviour? “It can be taught, but you have to start early and show by example. You can’t let children away with innocuous slights. It’s important to watch what you yourself say, and think through throwaway remarks.

“The book is to remind people to think twice about remarks they make – and don the muzzle if you have to. At some point we all have to look beyond the possible reasons that this happens and just stop doing it.”

The Twisted Sisterhood: Unraveling the Dark Legacy of Female Friendshipsis published by Ballantine Books; kellyvalen.com