Empathy for others, is a large part of what makes us “Human Beings”.
Lack of Empathy is an Alien or Reptilian quality.
Empathy does not register in their mind. Maybe it is because of Childhood Trauma. Maybe no one gave a shit about them, when they were a young child and really needed someone to care, but no one did. Childhood Abandonment Issues is one thing which Narcissists seem to have in common.