>>513777895 (OP)
Factors genetic and factors cultural.
They have higher tendencies towards psychopathy, and have never developed a philosophical concept of their own comparable to say, Ahimsa, or Christian Humanism.
Because these are essentially foreign concepts to them, attempting to impose them from the outside is a fragile short-lived thing.
They must experience from within, the interconnectedness of all living things, or else, forcing them to act in such a manner is no different to training an animal, to do something it does not understand the purpose of.
If you don't give it regular rewards, it will naturally revert.