Haven't read the book, so my idea of uncle Tom is more like uncle Rukkus from boondocks. Collective self-hate leads to a group based around human sacrifice, either through banishment, scapegoating or ritual murder (psychologically similar fates). Eating one's own is a phenomenon called a purity spiral. The inner party always sacrifices the outer party. This is the way of Satano-Communism and highschool girl cliques (basically the same thing).