What is the theme in Deviant: The Shocking True Story of Ed Gein, the Original Psycho by Harold Schechter?

The need for love is at the heart of this story in several ways, beginning with Ed's relationship with his mother. Though she seems to care little for exhibiting affection for her sons and is readily willing to berate them, she seems to fully expect their complete love and devotion. She goes so far as to teach the boys that all women - with herself as the sole exception - are evil and wicked.