1% of males are psychopaths. Fewer females are. Most are nonviolent. But virtually half of crimes like serial rape and killing, murdering of officers, etc are committed by psychopaths.
They do have some emotions, but usually about themselves than about others.
Nurture based explanations do not explain psychopathy (e.g. poor mothering, early trauma, etc).
It seems it is genetically inheritable.
Psychopaths are very rational. The rider serves the elephant - not the other way round.