One interesting way psychiatrists could go about the discovery of psychopathy earlier is by having people play the game The Sims behind closed doors and secretly monitor them. What a person would do in a simulated world with no consequences could be a good indicator as to their real life inclinations. This is just from my experiences though. I've gotten a lot of insight on myself from playing this game as a teenager. It went from highly ambitious and successful to utterly depraved real quick once the doors were closed and no one was around.