Simple trick to weed-out sociopaths, or those with sociopathic tendencies:

Only a sociopath will tell you confidently that they themselves are a good person. As they are above others, they don't need friends or family to reassure them that they are good. They know they are good, because they tell themselves they are good, hence they are good.

Non-cunts rarely, if ever, will state that they are good people. Most of the time, they ask friends or family "am I a good person?", and let them answer.

Arrogance/pride vs. humility, essentially.