What do the top horror movies all have in common?
They all have unforgettable soundtracks that elicit an immediate sensation of terror. As a matter of fact, if you view the films without any sound, they become a lot less scary.
But what is it regarding the music that renders it frightening? More specifically, if sounds are merely vibrations in the air, what is it about our biology that makes us respond with fear?
The Fear Response
With respect to evolutionary biology, there’s an evident survival advantage to the instantaneous identification of a detrimental circumstance.
Thinking takes time, especially 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 consciously.
Considering that it takes additional time to process and think about visual information, the animal brain is wired to respond to swifter sound-processing mechanisms—a trait that provides survival advantage and has been selected for in the wild.
And that’s exactly what we see in nature: a large number of vertebrates—humans included—emit and respond to harsh, nonlinear sounds and vocalizations when frightened. This results in a virtually instant 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 beyond their normal range.
Our brains have evolved to recognize the attributes of nonlinear sound as unpleasant and indicative of dangerous circumstances.
The interesting thing is, we can artificially simulate a wide array of these nonlinear sounds to get the same instant fear response in humans.
And so, what was once a successful biological adaptation in nature has now been co-opted by the movie industry to produce scarier movies.
Music and Fear
We all are familiar with the shower scene from the classic film Psycho, and it’s definitely one of the most frightening scenes in the history of film.
But if you watch the scene without sound, it loses most of its impact. It’s only once you incorporate back in the high-pitched screaming and bone-chilling staccato music that the fear response becomes fully engaged.
To demonstrate our instinctive aversion to this nonlinear sound, UCLA evolutionary biologist Daniel Blumstein conducted a study assessing the emotional responses to two types of music.
Study participants listened to a collection of emotionally neutral music scores and scores that contained nonlinear properties.
As predicted, the music with nonlinear elements aroused the strongest emotional responses and negative feelings. This response is simply an element of our anatomy and physiology.
Whether Hollywood understands this physiology or not, it appreciates intuitively that the use of nonlinear discordant sound is still the best way to get a rise out of the viewers.
Want to observe the fear response in action?
Check out these 10 Essential Horror Movie Scores.