Don't necessarily think in term of advantage, but rather in term of probability it will stay in the gene pool. If psychopathy is genetically linked to say, a b

Don't necessarily think in term of advantage, but rather in term of probability it will stay in the gene pool. If psychopathy is genetically linked to say, a better resistance to cold or hunger, then it might stay even with the disadvantage of psychopathy, just because people with it will survive better.