Consistency = Trust

"I think that sociopaths (particularly young ones) actually feel happier and thrive better in a world of clearly defined boundaries; when rules are consistently enforced, the child will just start to take them as a given.  I certainly did. I think simple cause-and-effect rules with clear, predictable outcomes for compliance or violation encourage the young sociopath to think of life as an interesting puzzle that can be gamed.  As long as the young sociopath believes that she can acquire some advantage through skillful planning and execution (and finds some level of success, which I feel is almost a given), she will stay committed to the structure of the game you have set up...

The worst thing that parents can do is to be inconsistent.  It makes the child sociopath think that the game is rigged; in that case, it doesn't matter what he does, except to the extent that he can out-cheat the cheater (typically the parent).  Providing me a system defined by clear incentives, my parents laid out a way for me to gain positive benefits while exercising my sociopathic traits.  I didn't have to rely on the soft intangibles of empathy or emotion to get what I needed."

from Confessions of a Sociopath by M.E. Thomas