What is the theme in Genie: A Scientific Tragedy by Russ Rymer?

Child Abuse is a theme. Genie was strapped to an infant potty chair for more than a decade, from the time she was nearly two until she was thirteen. Genie was not allowed to go outside and play. She had no toys except for a rain coat she occasionally was allowed to fondle. Genie had no one to speak to. Genie did not learn to speak, to control her bowels, to eat properly. Genie was beaten when she made noise and frightened by the sound of a barking dog when her father was annoyed with her.