Hereditary Movie Ending Explained

As for the repeated references to heads, when Annie details her mother’s life, the death of all the men around her is earmarked with the belief that ‘she was trying to put people inside them,’ an idle statement that makes far more sense when we learn of her devil worshipping ways. However, maybe it gives way to more than simple sentiment. The head is clearly an important part of this ritual - with the three generations of women left bare from the shoulders up by the end of the movie.

What if the only way to purge oneself of the demon is to be decapitated? This would also stand to prove the theory that he has been passed down through the three ages of the Graham family until able to get to Peter, with each member he’s inhabited having to lose their head for him to be freed and move on. Paimon clearly takes over the minds of those he is near, making them make irrational decisions and suffer from confronting dreams - perhaps death isn’t simply enough to rid oneself of his curse.

Losing one's head, so to speak, would also be representative of the mental illness plaguing all of Annie's family members. Schizophrenia, dissociative identity disorder, dementia, and depression are all traits that are referenced as coming from those related to her, and then mirrored throughout the actions of the Graham's within the film.

In any case, it proves that this demon possession, and by extention, mental illness, is much like the title of the film: Hereditary. The bloodline link is inescapable for these women, just as much as their inevitable decapitation.