Starting in the late 1800s, horror films have given birth to countless subgenres that oftentimes reflect a certain 
point in history. For centuries, stories originating from folklore and religious beliefs have sought to channel the power of fear and disgust to provide entertainment. The nature of horror movies means that they’re often subject to censorship and controversy, and the horror film genre has often found itself pushed away from the mainstream. They rarely receive critical acclaim – only six have ever been nominated for the Best Picture Academy Award.
Many ever present horror features such as ghosts, demons, zombies, monsters, madness, and apocalyptic events were already well established in ancient folklore and texts from around the world. Sources include Ancient Greek and Roman texts and even the Bible. The driving force behind horror has always been to draw inspiration from mythology, urban legends, fairy tales and literature.
Horror films may incorporate incidents of physical violence and psychological terror; they may be studies of deformed, 
disturbed, psychotic, or evil characters; stories of terrifying monsters or malevolent animals; or mystery thrillers that use atmosphere to build suspense. The genre often overlaps science-fiction films. Horror offers us a fictional space in which we can share and evaluate our collective fears.
The 1910s and 20s saw Germany arise as a big influence on the horror genre, with German Expressionist art evident in the aesthetic of many films. Paul Wegener’s ‘The Student of Prague’ and ‘Golem’ films were notable, while films such as ‘The Cabinet of Dr. Caligari’ and the Dracula adaptation ‘Nosferatu’ are regarded as masterpieces and greatly influenced future American horror films.
Widely considered to be the finest era of the genre, the two decades between the 1920s and 30s saw many classics being produced and can be neatly divided down the middle to create a separation between the silent classics and the talkies. On the silent side of the line, you’ve got monumental titles such as The Cabinet of Dr. Caligari (1920) and Nosferatu (1922), the first movies to really make an attempt to unsettle their audience. With perhaps more subgenres than any other branch of fictional filmmaking, it’s difficult to see how anyone can expand or advance on anything that has come before in cinematic horror.
The 1930s also marked the first time that the word ‘horror’ was used to describe the genre—previously, it was really just romance melodrama with a dark element—and it also saw the first horror ‘stars’ being born. Bella Lugosi (of Dracula fame) was arguably the first to specialize solely in the genre. You can’t mention British horror without paying respects to Alfred Hitchcock, single-handedly responsible for establishing the slasher genre.
Once the silent era gave way to the technological process, we had a glut of incredible movies that paved the way for 
generations to come, particularly in the field of monster movies – think the second iteration of Frankenstein (1931), The Mummy (1932) and the first colour adaptation of Dr. Jekyll and Mr. Hyde (1931). George A. Romero emerged triumphant and kick started zombie movies in this period, having produced Night of the Living Dead in 1968 with just over US$ 100k. It went on to gross US$ 30 million, and the living dead rose in its wake.
The 1960s brought the unforgettable thrillers of Alfred Hitchcock. Psycho signaled a new era of increased psychological elements and violence in horror films. Later in the decade, George A. Romero’s ‘Night of the Living Dead’ broke boundaries and paved the way for a new wave of variety in horror movies in the 1970s and 80s, when the horror genre diversified and many classic films were produced. Rather than a technical genre, Gothic horror perhaps refers more to the aesthetics of films of this description. Films often borrow from European Medieval imagery, with such settings as ruined castles and decaying mansions commonplace.
The reason for this cultural obsession with religious evil during this period could fill an entire article on its own, but bringing it back into the cinema realm, we can boil the trend down to two horror milestones: The Exorcist (1973) and The Omen (1976). Supernatural horror was now very much back in vogue. Halloween, Friday the 13th, and A Nightmare on Elm Street are the most prominent examples, which became so successful that they spawned their own long-running franchises (the first time in the history of the genre that multiple sequels became commonplace.) Witches have a long history of 
mischief in folklore. They use the power of magic to cast spells on their victims turning them into all kinds of tortured beings. Similar to the paranormal genre, witchcraft uses supernatural elements to create fear.
‘The Texas Chainsaw Massacre’ and John Carpenter’s ‘Halloween’ were the first ‘slasher’ movies. Many consider the slasher film one of the most sensational and popular genres. You can trace its origins to John Carpenter’s Halloween in 1978. This genre introduced a new batch of fearsome characters that began to replace traditional figures such as Dracula and Frankenstein’s Monster in viewers’ nightmares. Serial killers such as ‘A Nightmare on Elm Street’s’ Freddie Kruger and ‘Halloween’s’ Michael Myers spread a new dimension of fear. Shockingly violent films involving mutilation and torture hit the screens during this time. Movies such as ‘Saw’, ‘Hostel’, and ‘Wolf Creek’ were commercially successful.
Vampires, aliens, and giant sea creatures are all antagonists in the Monster movie genre. Unlike their supernatural counterparts, monsters can wreak havoc on a community of people in one fell swoop. Monsters terrorize and kill whatever is in their path and use their strength and size to destroy.
Rather than fearsome monsters or brutal gore, psychological horror films create fear by delving into the darker corners of the mind. They often involve characters losing their grip on reality, emotional manipulation, or even mental disorders. The main characters in these types of horror movies are mentally unstable or emotionally disturbed to the point of being violent. The power of these films lies in the fact that they play on real fears and emotions – it could happen to us. Perhaps ‘The Shining’, a 1980 adaption of the Stephen King novel, is the most notable example of psychological horror, as it depicts Jack Nicholson’s character descending into madness.
Some films create fear and suspense without actually showing audiences much – noises in the dark, objects moving without explanation, strange symbols appearing, and so on. ‘Found-footage’ films do this particularly well. ‘The Blair Witch Project’ was hugely successful in 1999 and paved the way for the later success of ‘Paranormal Activity’.
Zombie movies cross multiple horror subgenres. One part monster movie, one part possession, zombie thrillers make a perfect cocktail of terror. Somehow they are the most difficult villain to kill off and just keep coming back for more. These corpse-like characters are cannibalistic by nature and can infect their victims with a single bite. Shows like The Walking Dead created a cult following for the zombie genre of horror.
Horror movies contain psychological tricks that create illusions of suspense and danger through the manipulation of images, sound, and story. Although your brain is aware that the threats aren’t real, your body simultaneously registers them as if they are. Horror films are designed to elicit certain emotions such as tension, fear, stress, and shock. Although adrenaline contributes to the overall experience of the movie, the elevated states can make it harder to sleep. For sensitive individuals, sleep can also be impaired by internalizing the images [from movies] into dreams. This is the dark side to horror movies.
