The costumes and make-up in horror are super important since they can be broken down into parts.
What filmmakers want their audiences to differentiate the protagonist with the antagonist; they will try to make it obvious for the audience to know which side they should be rooting for. They want them to feel at the edge of their sit throughout the movie.
Further, if the protagonist are on the weaker side they will feel sorry for them more easily, and if anything bad happens to them they’ll feel even worse. Audiences will be able to be pulled into this fantasy world where they genuinely care about the wellbeing of the fictional characters; which makes the film more impactful in the long run.
Verisimilitude – the appearance of being true or real.
It is important for a film to have verisimilitude because it stands for he appearance of reality or truth. For instance, if a film resorts into using unrealistic concepts that have been done countless of times on their project, it will ruin the movie for audiences, they will be sort of pulled out of the film since they know it is unrealistic. However, with twice as good make-up and costume designs the movie will seem more scary since the make-up is more realistic.
To use make-up and costumes effectively, movies need to support stereotypes that audiences already associate with. For instance, if a character gets hurt badly on one part of their body, viewers know that must be excruciating and they will be cringing thinking of how much that would hurt; it is the make-up and especial effects team to make it seem realistic by applying certain amount blood on the wound according to how big it is; which could leave audiences feeling nearly sick. If blood is splattered on their face it means that they are in great danger. And since make-up artist possess more resources than before, such as technology, the final product is much better bringing more emotion out of audiences.
Characters will look as human as possible through make-up and costume trickery. Costume designers want the audience to be scared; so the y will have a ghost dress in white to make them look innocent, like they couldn’t hurt a fly because the thought pf having someone unassuming commit horrible murders is terrifying. The skin on display will look completely pale but their eyes; they want to make them seem real.
Source: https://cine-vue.com/2018/04/why-costumes-and-make-up-are-still-so-important-to-horror-films.html
AS Media Studies 