Typically, they are likely to have elements of the unknown. The fear of the unknown is a common characteristic in horror. For example, an unexplained sound or a shadow that moves on its own.
They are often filled with suspense. The authors build up tension to keep readers on the edge of their seats.
Often, they create a sense of unease and fear quickly. For example, they might start with a strange or disturbing setting like a haunted house or a desolate graveyard.
They are concise. Usually, they quickly establish a spooky or menacing situation. For example, in a short horror story, the horror might start within the first few sentences, like a strange noise in an empty house right at the start.
Many 1948 horror short stories often had a sense of mystery. They were set in rather ordinary settings which made the horror more relatable. For instance, like 'The Lottery', it was set in a small town that seemed normal at first glance.
They probably had relatable characters. Since these were popular, the characters must have been easy for readers to connect with, whether they were ordinary people facing everyday problems or extraordinary characters in unique situations. These characters' emotions and experiences would resonate with a wide range of readers. Also, the themes would be relevant. Themes like love, loss, friendship, and the search for identity are common and always attract readers. In 2014, short stories with these themes could have easily gained popularity.
One characteristic is the use of the unknown. For example, in 'Alien', the alien creature is something we don't fully understand, which creates fear. Another is the sense of isolation, like in 'The Thing' where the characters are stuck in an Antarctic base with a deadly shape - shifter.
Popular Japanese horror stories often feature elements of the supernatural. In 'Tomie', Tomie's regenerative powers are beyond the realm of normal human abilities. Also, they usually create a sense of isolation. In many of these stories, the characters are alone or in a small group, which heightens the fear. For instance, in 'Dark Water', it's mainly the mother and daughter facing the horror alone in their apartment.
Many of the latest short horror stories often rely on psychological horror. They play with the reader's mind, creating a sense of unease through things like paranoia and the unknown. For example, a story might have a character who is constantly being watched but can't figure out by whom.