Psychopathy is actually an innate condition in some humans, and I do not think that animals can be 'psychopathic'. Also, cats were never tamed. They just came to us because of the all the rodents. But I guess we are all not as kind as we think.
As the Joker wisely said: You see, their morals, their code, it's a bad joke. Dropped at the first sign of trouble. They're only as good as the world allows them to be. I'll show you. When the chips are down, these... these civilized people, they'll eat each other.