I think it depends on your age and maturity because a lot of negative effects come out of watching horror movies. Some people develop anxiety, seizures, depression, and other emotional/physical disorders. Unless you aren't afraid and not much scares you, but especially for kids you may be paranoid or frightened.
I think that they shouldn't because some may be way to young to see these kinds of things. They could get scared for life, based on what I have seen because I hate horror movies. They would never come by you again if you set them up with it, they will never forgive you. BTW, Hakuna is my best friend/ bae.