Do Shooters and Presidents Dream of Electric Sheep?

Evidently, the humanoid robot consisted of a solitary predator.

― Philip K. Dick

We puzzle over why a wealthy man would become a mass shooter, or a wealthy president tell a grieving widow her dead husband wished to be in harm's way.

It's the absence of empathy―a condition natural to solitary predators.

Empathy is a new word in English, only 110 years old. 

It came into the language thanks to philosophers of art, who borrowed the word from the Greek empatheia, meaning "passion." They believed our ability to appreciate works of art stems from our ability to project "fellow feelings" into them.

Novelist Philip K. Dick, in Do Androids Dream of Electric Sheep? (adapted for the screen as Blade Runner), imagined that manufacturers in 2021 will purposely omit empathy from androids' programming; and thus, a simple "empathy test" will be able to prove who's an android and who's a human.

Early in the book, Dick portrays the main character, the policeman Deckard, reflecting on the ease with which the test can detect an android:

He had wondered, as had most people at one time or another, precisely why an android bounced helplessly about when confronted by an empathy-measuring test. Empathy, evidently, existed only within the human community, whereas intelligence to some degree could be found throughout every phylum and order including the arachnida. For one thing, the empathetic faculty probably required an unimpaired group instinct; a solitary organism, such as a spider, would have no use for it; in fact, it would tend to abort a spider's ability to survive. It would make him conscious of the desire to live on the part of his prey, Hence all predators, even highly developed mammals such as cats, would starve. Empathy, he once had decided, must be limited to herbivores or anyhow omnivores who could depart from a meat diet. Because, ultimately, the empathetic gift blurred the boundaries between hunter and victim, between the successful and the defeated.