Michael Shermer unpacks our fascination:
Zombies, for one thing, fit into the horror genre in which monstrous creatures—like dangerous predators in our ancestral environment—trigger physiological fight-or-flight reactions such as an increase in heart rate and blood pressure and the release of such stress hormones as cortisol and adrenaline that help us prepare for danger. New environments may contain an element of risk, but we must explore them to find new sources of food and mates. So danger contains an element of both fear and excitement.
We also have a fascination with liminal beings that fall in between categories, writes philosopher Stephen T. Asma in his 2009 book On Monsters (Oxford University Press).
The fictional Frankenstein monster, like most zombies, is a being in between animate and inanimate, human and nonhuman. Hermaphrodites fall between male and female, and hybrid animals fall between species. Our innate templates for categorizing objects and beings are modified through experience, and when we encounter something or someone new, we check for category matches. Moderate deviation from the known category generates attention (friend or foe?), Asma says, but a “cognitive mismatch” elicits both dread and fascination. Add the emotion of disgust triggered by slime, drool, snot, blood, feces and rotting flesh, and we may find ourselves both repelled and drawn to such liminal creatures.
(Photo: Tor Johnson as a zombie in the 1959 cult movie Plan 9 from Outer Space, via Wikimedia Commons)