Both “The Walking Dead” and “American Horror Story” can be categorized under the “horror” genre, and both are doing well ratings-wise.

WalkingdeadIt would be wrong, however, to draw comparisons between the two, inasmuch as they appear to be working for decidedly different reasons.

The AMC show — once you get past the zombies, whose appearances are actually infrequent — is essentially about relationships among a small group of people, with everything heightened by the constant threat of death in a world that has, as one character put it, “gone to shit.” It is understated, occasionally darkly funny and — in terms of this Sunday’s midseason finale — even strikingly poignant.

“Horror Story,” by contrast, is a frenzied fever dream, a show awash in can-you-top-this? excess. In ways, it betrays series co-creator Ryan Murphy’s worst impulses on the later seasons of “Nip/Tuck,” which at least had the excuse of being about a world — plastic surgery — that provided cover for and helped explain away its over-the-top characters.

Although the plot has filled in over the last several weeks, “American Horror Story” has only become more convoluted, largely because of the number of characters who have turned out to be ghosts, and the fuzzy rules about their ability to physically interact with the living. The show still exhibits glaring lapses in logic, however, starting with its contortions to keep the central couple — played by Dylan McDermott and Connie Britton — in a house from which any semi-normal people would have long since fled.

While I can see AmericanHorrorStory-langewatching the FX series simply to see what extremes it will go to next — and I confess to being fascinated, perversely, on that level — it’s the complete opposite of “Walking Dead,” which practices restraint in a setting that could easily give way to gratuitous gross-out sequences and insane sprees.

There’s room for both, obviously, but as executives look to cash in with the inevitable knockoffs and copycats likely to spring from future development crops, they would be misguided to conflate the success of the two into a trend.

Because whatever the listings might say, not all horror stories are created equal.