The four causes that we identify in the book are parenting, celebrity culture, media and the Internet, and easy credit. For example, with parenting, in an attempt to raise kids with self-esteem, many parents will tell their kid they're the best ever and they'll treat them like royalty, placing the child at the center of the household. In a limited way, that's fine, but it's often taken too far. When you put a kid on a pedestal, that type of parenting, it's been shown, leads to narcissism.