"Odd Girl Out: The Hidden Culture of Aggression in Girls" by Rachel Simmons is a nonfiction book published in 2002 that delves into the world of aggression among girls. This hardcover novel explores the social dynamics and psychological factors that contribute to aggression in young girls, offering insights into this often misunderstood aspect of childhood. With a focus on children's studies and social psychology, this book provides a compelling examination of the complex issues surrounding aggression in the world of young girls.