In previous chapters, the girls have been mostly angry - rebelling, disobeying, yelling, hitting, etc. In this chapter, the author talks about girls who are depressed and suggests that anger and depression have the same source. According to Pipher, what determines whether a girl's troubles are expressed as anger or depression

Anger is a fleeting feeling, but depression is something that lingers, causing remorse and negative feelings that will not go away.

Explanation:

Although anger can be a symptom of depression, it is a fleeting feeling. Anger is explosive and can cause shame and remorse after it passes, but it never lasts forever. Anger always ends in an hour, but depression does not, because it can keep a girl in a state of anger for long periods of time and promoting deep, debilitating, endless remorse and anguish.