I was reading the STASI guidelines that were used in the 70's to destroy the motivation and spirit of political opponents, and asking myself, from the psychological point of view, what's the best way to break an individual and rend him a harmless piece of cattle that works without ever questioning the feeding hand (a.k.a a lemming or a NPC)
The STASI manual gives some interesting hints:

1) Social isolation
2) Creation of artificial conflict that can't be countered with logic (creation of demoralizing ideologies that can't be countered without being exposed)
3) Organized failure in life (getting fired, getting kicked out of apartment / home etc).

Is social isolation more effective than psychological abuse by imposition of unnatural ideologies that push people to oppose their morals and natural dispositions?