All the great movies like Lord of the Rings or also Game of Thrones and other fantasy or SF stories have the same theme: it's which of the forces is going to get you and will make you acting against what is sacred or holy. Or, in more secular terms, what is against your conscience.
I am not familiar with "The trigger effect". "Lord of the flies" I read a long long time ago. Did not like the emotions it caused me, if I remember correct.