What do the top rated horror movies all have in common?
They all have memorable soundtracks that arouse an instant feeling of terror. In truth, if you view the films without any sound, they become a lot less frightening.
But what is it about the music that makes it frightening? More specifically, if sounds are merely oscillations in the air, what is it about our biology that causes us to respond with fear?
The Fear Response
In regard to evolutionary biology, there’s an evident survival advantage to the instantaneous detection of a threatening circumstance.
Thinking is time consuming, particularly when you’re staring a ravenous lion in the face. When every second counts, you don’t have the time to stop and process the information deliberately.
Considering it takes additional time to process and contemplate visual information, the animal brain is wired to react to quicker sound-processing mechanisms—a trait that offers survival advantage and has been selected for in the wild.
And that’s precisely what we discover in nature: several vertebrates—humans included—emit and respond to harsh, nonlinear sounds and vocalizations when alarmed. This generates a nearly instantaneous feeling of fear or anxiety.
But what is it about nonlinear sound that makes it frightening?
When an animal screams, it produces a scratchy, irregular sound that stretches the capacity of the vocal cords past their typical range.
Our brains have evolved to distinguish the properties of nonlinear sound as abnormal and suggestive of dangerous situations.
The fascinating thing is, we can artificially reproduce a variety of these nonlinear sounds to get the same instantaneous fear response in humans.
So, what was once a successful biological adaptation in nature has now been co-opted by the movie industry to manufacture scarier movies.
Music and Fear
We all are familiar with the shower scene from the classic film Psycho, and it’s probably one of the most frightening scenes in the history of film.
But if you watch the scene without sound, it loses the majority of its impact. It’s only when you incorporate back in the high-pitched screaming and bone-chilling staccato music that the fear response becomes thoroughly engaged.
To confirm our natural aversion to this nonlinear sound, UCLA evolutionary biologist Daniel Blumstein carried out a study examining the emotional responses to two types of music.
Participants in the study listened to a collection of emotionally neutral scores and scores that contained nonlinear elements.
As predicted, the music with nonlinear elements aroused the most powerful emotional responses and negative feelings. This response is simply a natural part of our anatomy and physiology.
Whether Hollywood comprehends this physiology or not, it knows instinctively that the use of nonlinear discordant sound is still the most effective way to get a rise out of the viewers.
Want to witness the fear response in action?
Check out these 10 Essential Horror Movie Scores.