The only time a person can make a choice is when he has a friend or relative or fellow citizens that tries to set him straight and gives him the opportunity to make a choice.
When a person is surrounded by a monolithic culture, where everyone tells him what he already thinks, then he has no choice to make.
At that point, the only thing stopping him from doing bad things is the punishment that the society at large will hit him with if he does it.
If he no longer fears that punishment, or think the whole society at large is a farce in the first place, just thing to be toyed with and destroyed, then there is nothing to restrain him.
Possibly, though I would contend a truly monolithic culture has never existed. Certainly our present society is not monolithic. Possibly it is less so than ever before, with the interwebs providing a truly effective way, for the first time in history, for those of uncommon beliefs to find each other and develop their own subcultures.
With FR a leading example.