It seems to me that monsters du jour tend to represent social anxieties. Now, the Victorians were prudish about sex, but very open about death: death watches, open caskets, public grieving, periods of mourning. So vampires like Dracula and Varney tended to represent a fear of sex rather than a fear of death. A zombie wouldn’t have been very scary to a Victorian: it’s just like a common or garden everyday corpse except that it walks around. These days, we’re open about sex, but repressed about death. So vampires aren’t scary: they’re being relegated to cute entertainment for tweens. But zombies are scary because they remind us of death. They don’t think. They look hideous. They’re the thing we try desperately to avoid with botox and superfoods and cosmetic surgery and pills, but will always succumb to in the end: death.