Rachel Simmons, author of New York Times bestseller “Odd Girl Out: The Hidden Culture of Aggression in Girls,” discussed personal experiences with female aggression as well as her research for the book on Monday night.

Simmons, who has appeared on “The Oprah Winfrey Show,” “Today,” “Dateline NBC,” NPR’s “Diane Rehm Show” and “Talk of the Nation,” regularly lectures to girls, parents and teachers around the country about female aggression and its implications for girls’ and women’s lives. She spoke to about 50 students, faculty and community members in the Marvin Center Ampitheatre as a part of the National Leadership Series.

The Student Activities Center and New York Life Insurance Company co-sponsored the event, which was the third in a series of leadership events throughout the year. The purpose of these lectures is to “bring a diverse group of leaders in different areas to appeal to different students,” said Martine Philogene, SAC coordinator for student involvement.

“Odd Girl Out” discusses the common social expectations of girls – that they must value friendships and not express anger. A cultural environment that does not allow girls to acknowledge conflict creates “a hidden culture of silent and indirect aggression,” said Simmons.

She said she was motivated to conduct research on girls’ aggression because most other studies on aggression are limited to boys. To conduct research, she surveyed about 100 parents, teachers and counselors, and 300 girls ages 10 to 14 from 30 schools around the country.

“When girls are mean to each other, when they strike out against each other, the behavior is often termed a rite of passage. What it is rarely called is ‘aggression,'” Simmons said. “The way that aggression has been defined has been behavior that has been disruptive of the social order. You will find that girls’ aggression can be particularly non-disruptive and slip below the radar.”

The book also discusses three types of aggression girls disproportionately engage in – social aggression targeting social status and self-esteem, indirect aggression toward a person anonymously or with the pretense of not intending harm, and relational aggression using friendship as an excuse to get away with harming someone.

Simmons said, according to her research, girls are more likely to hurt friends or acquaintances than boys, who are typically aggressive toward people they are unfamiliar with.

“For girls, social power is relational power. It’s who you know, who knows you and who’s going to back you up when you have a conflict with someone,” she said.

Simmons also said society neglects victims of female aggression because it sees emotionally aggressive behavior among girls as acceptable.

She explained raising girls differently than boys, which usually includes teaching them to shy away from conflict and anger, can cause female children to release aggression in various ways.

“The type of rage that is emitted is disproportionate to the crime and goes on longer,” Simmons said. “We help to perpetuate a culture in which female aggression is seen as dysfunctional.”

Simmons promotes “truth-telling” as a strategy for dealing with destructive patterns of behavior. She said she hopes society begins to support emotional honesty in girls and public discussions on bullying.

“I envision a world that will expand their definition of what bullying and aggression mean. I don’t believe in making girls nicer. I just believe in allowing them to deal with their anger in appropriate ways,” Simmons said.

On the future of aggression in girls, Simmons said, “Aggression is universal. I’m not saying you can eliminate this behavior. As long as we allow it to go on with no strategies to deal with it, the more we allow that behavior to perpetuate. You can’t expect girls to compete on the same level as boys if they don’t have the same tools to get there.”

Simmons’ lecture received varied responses.

“I found it informative, and I thought it was a good beginning of a much longer dialogue,” said Laura Serico, a education graduate student. “It is definitely rooted in her experience, so it’s not the whole story, but it’s important because it validates the experiences of the girls.”

“I didn’t like it. I felt that (Simmons) was immature and saw things with a narrow focus, like the way she presented mostly only one small segment of society – mostly white middle class,” audience member Marlis Carter said.

Simmons discussed the limitations of her study at the reception following her lecture, saying, “The data was not empirical, it was primarily anecdotal and interview-based. Also, I wish that I had interviewed more boys and bullies because it’s clear that boys are perpetrators of this behavior also, and this book favors victims’ experiences more, but it’s universal and it’s hard to convey that when everyone you interview is talking about being a victim.”

She also said the people she interviewed were self-selected, meaning they came forward for interviewing voluntarily, so the group studied was not a random sampling.

Simmons wrote the book between 1999 and 2002 while in graduate school at Oxford University. She grew up in the Maryland suburbs of D.C. and attended Vassar College, where she now directs Sidwell Friends School’s summer program The Girls’ Leadership Institute, a program based on empowering girls to promote independent decision-making.