What do the top rated horror movies all have in common?
They all have memorable soundtracks that arouse an instant feeling of terror. Indeed, if you watch the films without any sound, they become a great deal less frightening.
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
In regard to evolutionary biology, there’s an obvious survival advantage to the immediate identification of a threatening circumstance.
Thinking takes time, 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 consciously.
Given that it takes longer to process and ponder visual information, the animal brain is wired to respond to quicker sound-processing mechanisms—a characteristic that provides survival advantage and has been selected for in the wild.
And that’s exactly what we find in nature: several vertebrates—humans included—produce and respond to harsh, nonlinear sounds and vocalizations when frightened. This yields a virtually instant sensation 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 typical range.
Our brains have evolved to discern the attributes of nonlinear sound as unpleasant and suggestive of hazardous circumstances.
The fascinating thing is, we can artificially reproduce a variety of these nonlinear sounds to bring about the same immediate fear response in humans.
So, what was once an effective biological adaptation in the wild has now been co-opted by the movie industry to manufacture scarier movies.
Music and Fear
We all know the shower scene from the classic movie Psycho, and it’s definitely one of the most frightening scenes in the history of film.
But if you view the scene on mute, it loses the majority of its impact. It’s only once you incorporate back in the high-pitched screeching and bone-chilling staccato music that the fear response becomes thoroughly engaged.
To reveal our natural aversion to this nonlinear sound, UCLA evolutionary biologist Daniel Blumstein conducted a study assessing the emotional reactions to two types of music.
Study participants listened to a collection of emotionally neutral music scores and scores that included nonlinear elements.
As expected, the music with nonlinear characteristics aroused the strongest emotional reactions and negative feelings. This response is simply a part of our anatomy and physiology.
Regardless of whether Hollywood comprehends this physiology or not, it knows instinctively that the use of nonlinear disharmonious sound is still the most effective 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.