Stupidity is a valued staple of the horror film. Were it not for the brain-cell-deprived masses, who would open the doors where they hear screams? Who would read the forbidden texts that supposedly summon ancient demons? Who would venture to the campground where the hideous murders occurred? Who will attempt to capture the mutated beast, assuredly thinking that they are the ones who can calm it?

We are thankful for them, as they are the ones who bring about the more participatory aspects of the genre. “What are you thinking!?” “I’d be out of there way before them!” “Don’t go in there!” we’ve been known to whisper - or yell - at the screen. It gives us a sense of superiority in such films, as we would never be dumb enough to do such things, right? Yet, we continue to plop down cash and keep coming back for more, so...

And there are two films at the box office this Halloween where stupidity is doled out like Snickers bars to hungry trick-or-treaters. “Paranormal Activity 4” is the latest chapter in the profitable found-footage franchise, and while the other fright flick, “Sinister,” is not part of a franchise or remake, all the elements in it are awfully familiar.

“Sinister” stars Ethan Hawke as a writer, Ellison Oswalt, who thinks it’d be a grand idea to move his unsuspecting family into the very same home in which lived the murdered family that’s the subject of his next book. Why? Well, let’s just say after sitting through all of “Sinister,” the move represents one of the more intelligent ones he makes.

While unpacking, Ellison comes across a solitary box in the attic with a projector and a stack of film reels whose content looks like the Manson Family holiday vacations. Does Ellison turn the material over to the local police, as he is now in possession of decades’ worth of evidence of unsolved murders? Does he quickly call his real estate agent and ask to be moved to some not-so-foreboding abode? Nope. Perhaps he’s looking for just a few more warning signs.

How about a scorpion? A snake? Horrible night terrors that seem to plague his young son? His daughter befriending the dead girl who used to live in the house? Any one of these would cause the person of average intelligence to pivot and head as far away as possible. But, in keeping with genre tradition, Ellison believes he can unravel this mystery on his own, resulting in his next big best-seller, family and personal safety be damned.

For the audience, this means we will be given ample opportunity to get scared as he blissfully ignores each and every paranormal clue left, sometimes quite literally, at his doorstep. But they are not the lasting, check-the-backseat-of-the-car scares that occur after you leave the theater. They are champagne-bottle-pop scares: meant to give you a momentarily accelerated pulse rate, but leaving no lingering chills.

It certainly doesn’t help that Hawke’s character is a crappy husband and father, narcissistically remaining in a situation that repeatedly puts his entire family in jeopardy so he can write a best seller. He makes Jack Torrance from “The Shining” look like Father of the Year by comparison. There’s a ton of other faults to be found in “Sinister,” right down to the illogical mythology and powers of the main demon. But it seems audiences (and critics) are so hungry for original scares, they’ll set aside almost everything for the sake of a jump or two.

Or three, or four ... which is the case for the “Paranormal Activity” franchise, now in its fourth installment. There’s not much new in terms of revelations, just more variations on the theme of security-cam horror. And it features not one central idiot, but an entire houseful of them.

It’s particularly frustrating, as after the rather vapid first two entries, the third film in the franchise seemed to pick up steam by delving into some backstory of its characters and constructing a compelling narrative. While still filmed by the same directors of the third installment (Henry Joost and Ariel Schulman), the fourth feels more like a bridge picture, as we are introduced to some random Nevada family that is the recipient of some spooky thuds in the night that are vaguely related to the original characters.

Our heroine is Alex (played by Kathryn Newton), an attractive suburban teen who seems part cyborg, as she’s always fused to some technical device, be it her iPhone, laptop, video camera, etc. She shares a home with her mom and dad and younger brother Wyatt (played by Aiden Lovekamp). When the family’s new neighbor is unexpectedly carted away by ambulance, the woman’s young son Robbie (played by Brady Allen) is left in their care.

Since most other filming techniques have been exhausted in the previous installments, “4” seems desperate to come up with an inventive camera trick to hook its audience. Prepare to be dazzled by the “Haunted Xbox Kinect Cam.” Yup. Now a blatantly obvious video game product-placement tie-in provides the scares.

And there are a few jumps to be had, no doubt, but none any different from the random crashing noise, creative-editing cuts and random-appearing animals that have populated the first films (and about 100 other horror flicks).

It does dabble in a larger story which will undoubtedly be addressed next Halloween in the fifth installment. There’s a mysterious circle with a triangle in it that appears in random images, so apparently the ghost is a recovering alcoholic? No, it points to some ancient occult nonsense, but it’s only vaguely addressed.

I suppose those looking to get a comfortable rush for Halloween will find both “Paranormal Activity 4” and “Sinister” enough to provide a jolt, but like all the good candy found in your bag after a night of trick-or-treating, they will be but a faint memory the following day.