Sorry to overstay my welcome on this post, Caitlin. But Hedges touched on this same topic recently, though not in terms of psycopathy.

The paragraph

“Immanuel Kant coined the term “radical evil.” It was the privileging of one’s own interest over that of others, effectively reducing those around you to objects to be manipulated and used for your own ends. But Hannah Arendt, who also used the term “radical evil,” saw that it was worse than merely treating others as objects. Radical evil, she wrote, rendered vast numbers of people superfluous. They possessed no value at all. They were, once they could not be utilized by the powerful, discarded as human refuse.”

is from

The Age of Radical Evil