Monsters from the Id by E. Michael Jones
In Monsters from the Id, E. Michael Jones argues that the horror genre originated with Mary Shelly's Frankenstein as a reaction to the Enlightenment, and in particular, to the French Revolution and the sexual morality leading up to it. The revolutionaries began with high ideals (liberte, egalite, fraternite) but also embraced the sexual freedom that resulted from the rejection of Christianity. The revolution rather quickly devolved into the publicly sanctioned mass murder of the guillotine and the Reign of Terror. Shelly's mother had gone from London to Paris to experience the sexual part of the revolution though she had at best a mixed experience. Shelly herself lived a rather chaotic and ultimately unsatisfying life with her husband Percy Shelly, who was a deep devotee of Enlightenment thought and morals. Jones argues that Mary Shelly poured her guilt and unease into Frankenstein, making it a powerful indictment of the Enlightenment's adherence to loose morals and unfettered scientific exploration. For Jones, sexual liberation leads ultimately to violence and death.
Jones traces this trajectory from Dracula (where sexual promiscuity leads to the poisoning of one's blood by vampirism) to Weimar Republic Germany (where sexual decadence, among other factors, led to the rise of Hitler and his racial (i.e. blood) purity obsession) to 1930s-1950s Hollywood (to which many German film artists fled) and up to the modern day (with discussions of the Alien franchise as a cultural revolt against fertility, i.e. sexual responsibility). His argument is thorough and well-documented.
Unfortunately, his argument is also not convincing. He claims Frankenstein as the origin of horror, but what about the stories of the Golem or of Faust, which predate Shelly by centuries? Jones ties his theory of horror so closely to sexual liberation (which indeed is central to many horror tropes, themes, and stories) that the book reads more like searching for examples to validate his theory rather than discovering an insight that explains the history of horror. He delves too pruriently into his examples, often assuming details that can't be confirmed, for example what Mary Shelly thought about her husband or his first wife's suicide. His writing style is mostly scholarly but too often crosses a line into unnecessary details or speculative assumptions. The book winds up being unpersuasive.
While I agree that sexual liberation brings a host of problems, I hardly agree that it is the cause and the core inspiration for the horror genre. The book has a lot of interesting little bits here and there, but taken as a whole, it is unsatisfying.