It’s impossible to shame a psychopath, morally and/or ethically. They simply don’t have a conscience. They’ve learned to fake it to fool “The Rubes,” but they don’t feel it, and don’t understand it. You see this most commonly when Republican politicians and strategists accuse any altruistic act as an act to curry favor, or for personal gain. Because that’s what they would do. They truly can’t understand compassion or empathy, and think it’s a sign of stupidity. When one of these people shows you who they really are, run.