Naysayers Don't Appreciate Classic Horror

Rating: 8/10 (11 September 2018)

Ignore the negative reviewers - they want unimaginative plots with hackneyed jump scares at break-neck speed. This film knows how to build suspense with subtle, disconcerting occurrences amplified by a driving, menacing score. Hereditary moves at a deliberately slow pace to maximize anticipation while delivering enough twists and thrills to keep viewers riveted.
With Charlie being featured prominently in the trailer, her death so early on comes as a shock (though one can see it coming in the moments leading up to it). Peter is unreactive. Both he and Charlie were reserved and seemingly unresponsive to the events in their lives, but this could be due to the trauma of nearly having been killed by their unstable mother years before. When Charlie is killed, Peter immediately goes into shock. He doesn't call the police, he doesn't look at Charlie's body (let alone retrieve her head), he doesn't inform his parents - he just goes home and goes to bed. While naturally there would be an investigation (and likely counseling), Peter barely registers what is going on around him. We see the next few weeks through his catatonic state, which is possibly why we aren't shown the turmoil that ensues after such an unexpected and grisly death of a close family member.
Hereditary is more cerebral than I expected, and leaves viewers with lots of questions. Is Charlie actually possessed by a demon or her grandmother's spirit, or is she simply an introverted, troubled young girl trying to cope (i.e. by developing a clucking tic) with a distressing event that has strained her family's bonds? Is the family truly being plagued by demonic activity caused by Ellen's dalliance with the occult, or are Annie and her children battling mental illnesses that have been afflicting the family for generations? Is what we see terrifying supernatural phenomena, or paranormal delusions and hallucinations provoked by extreme stress and trauma? Who knows?
With the exception of the final 10 seconds (that should have been left on the cutting room floor), this movie exceeds expectations. It's refreshing to see a film that leaves viewers wondering instead of ruining its potential greatness by pandering to an audience with limited intelligence and patience by explaining mysterious plot points and making every minor detail a clunky foreshadowing vehicle.
The story and score are reminiscent of The Skeleton Key and The Shining, respectively, so I imagine if you liked both of those, Hereditary will take its place alongside them in your horror/thriller repertoire.