Fridge Horror
- Mommy tells Alice in the middle of the movie, "You kids will be the death of me." Later at the end of the film, the kids under the stairs attack Mommy, Fool blows up the house and kills Daddy, and Alice stabs Mommy.
- Hopefully, Alice can put together a cogent statement for the police, because otherwise, the end of the movie is going to look to the police like a mob of black people going out and killing a wealthy white couple and looting their house...
- Only until they actually get a look inside the house and discover all the death-traps, Torture Cellar prison cells, and those Leroy steaks in the fridge.
- As much abuse as the eponymous people have taken, it's a disturbing thought that a group of cannibals that have been kept from all normal human contact nearly their entire lives are simply being allowed to roam free without any form of rehabilitation being offered.
- Daddy has a clearly unhealthy interest in Alice, as seen when she's shackled in the attic.
- Mommy and Daddy kidnapping children because they're unable to produce their own. However this counts as both Laser-Guided Karma and Fridge Brilliance as the incestuous relationships that led up to Mommy and Daddy have resulted in sterility.
Fridge Logic
- How are the eponymous People Under The Stairs going to survive now that they've escaped? They likely know nothing about modern life.
- There was that little TV set. Possibly Roach smuggles it down to the basement and lets them watch it sometimes.
- When the police go to the house after Fool's phone call, they find nothing - how the hell did the pair manage to patch up all the damage to the walls Daddy's shotgun blasts had caused? Why didn't the cops ask the neighbors about anything odd, such as the three gunshots from the exterior of the house? Or the recently-drained pond with glass at the bottom? The Police Are Useless indeed...
- Mommy and Daddy are implied to own the entire neighborhood. It's likely there aren't any neighbors close enough to overhear what happens in the house, because they may not choose to rent the adjacent properties to anyone.
- That said, Fool immediately noticed that everything in the kitchen has its own lock, something the police should have found suspicious (if not necessarily actionable).
- Mommy and Daddy are implied to own the entire neighborhood. It's likely there aren't any neighbors close enough to overhear what happens in the house, because they may not choose to rent the adjacent properties to anyone.
