In the history of film, Psycho is always spoken of as a turning point in the horror genre. It was, in two ways: one, it humanized the antagonist; and two, it manipulated the audience into shocking scream moments (e.g. the shower scene). This isn't really inherently good or bad — nor are the horror films that preceded it — but significantly informs the genre ever since.
Looking back, it's a little unbelievable to me that this shot wasn't in color. |
A more interesting genre is following from the humanization of the antagonist, towards a juxtaposition of the antagonist as an antihero. Interview with the Vampire is the earliest that comes to mind (though obviously the Anne Rice book came prior), a clear break with previous vampire movies (Nosferatu (both), Vampyr, Dracula*, et al), borne out in those that followed (Underworld (all), Van Helsing, The Vampire Diaries, True Blood, Twilight). These movies and shows may have a lot less respect than those that went before, but I think that is due more to a failure in the coexistence of money and art. In terms of narrative space, there's a lot more possibility that a mere evil being that must be killed. Honestly, the plot of Nosferatu or Vampyr is too simple and dull for the more demanding audience of today (not that they are not great films).
When the tendency of the humanization of the antagonist leads to proper antiheroes, who are no longer quite antagonists, and fall outside the realm of horror, we find all variety of ingenious cinema. House, Mad Men, The Hurt Locker, The Social Network – most of cinema today owes a debt to Psycho. For better and worse.
* Despite writing about it, I don't think I've ever seen Dracula. I'm sure I'll rectify that sooner or later; in the mean time, I'm reasonably sure the assertion holds.