Empathy is the key difference between humans and androids. While androids can match or best humans in most ways, they cannot empathize with anyone or anything. This key difference allows androids to pass as humans unless their empathy is specifically tested. Deckard’s job is to find and test androids, killing any that fail the Voigt-Kampff test for empathy. In this respect, empathy is the difference between life and death for an android. Even though they are aware of how important empathy is to their survival, they cannot comprehend empathy as an idea.

At first, this key difference is the driving force behind the narration. Since empathy is the defining trait of humanity, human characters feel compelled to show their empathy to the world. They own animals—both genuine and artificial—to perform empathy. Caring for animals is a reaffirmation of humanity. This demonstrative empathy adds a performative aspect to the definitive human trait; it is performed for the benefit of others, undermining the sincerity of the emotion by turning it into a social expectation rather than a genuine display of care or affection. Since real animals are rare and expensive, owning a real animal becomes a status symbol, almost implying that wealthy people are more human because they have a more visible means of expressing their empathy.