What are the motifs in The Prime of Miss Jean Brodie by Muriel Spark?

One recurring theme or motif in the novel, The Prime of Miss Jean Brodie, is that of friendship. From first appearances, the girls of the Brodie Set appear to be loyal best friends. But while the girls do have a strong sense of a bond, and while other believe the girls present a solid front, they do have some backstabbing tendencies as well as ulterior motives. This includes blatantly saying and doing things behind each others' backs in the attempt to get ahead or escape trouble. As the reader comes to discover, the girls grouped together really have individual lives, with different interests and beliefs. The only true thing tying them together is Miss Brodie, which allows them some semblance of friendship when they otherwise would not have been friends at all.