This is only true if you’re a firm believer in all nature, no nurture.
I didn’t claim “nurture” is not a thing, nor do I think the existence of “nurture” negates my claims.
I think while rare, an effective psychopath (I say effective because I’m not doctor diagnosing someone but I mean the same thing) could grow up to not be a sadist given certain other traits and a positive environment. A smart psychopath that doesn’t want to die in prison and had nice parents could decide that acting in a manner compatible with society will get them what they want more than the alternatives.