What do the top rated horror movies all have in common?
They all have memorable soundtracks that elicit an instantaneous sensation of fear. Indeed, if you view the films without any sound, they become a lot less scary.
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 react with fear?
The Fear Response
In regard to evolutionary biology, there’s an obvious survival advantage to the immediate detection of a dangerous circumstance.
Thinking takes time, particularly when you’re staring a hungry lion in the face. When every second counts, you don’t have the time to stop and process the information deliberately.
Since it takes a bit longer to process and contemplate visual information, the animal brain is wired to react to swifter sound-processing mechanisms—a trait that provides survival advantage and has been selected for in the wild.
And that’s precisely what we find in nature: numerous vertebrates—humans included—emit and respond to harsh, nonlinear sounds and vocalizations when frightened. This generates a nearly instantaneous 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 normal range.
Our brains have evolved to detect the characteristics of nonlinear sound as abnormal and indicative of life-threatening circumstances.
The intriguing thing is, we can artificially replicate a wide array of these nonlinear sounds to bring about the same instantaneous fear response in humans.
And so, what was once a successful biological adaptation in the wild has now been co-opted by the movie industry to manufacture scarier films.
Music and Fear
We all know the shower scene from the classic film Psycho, and it’s certainly one of the most frightening scenes in the history of cinema.
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 carried out a study examining the emotional reactions to two types of music.
Participants in the study listened to a selection of emotionally neutral music scores and scores that contained nonlinear elements.
As predicted, the music with nonlinear characteristics aroused the most powerful emotional reactions and negative feelings. This response is simply an element of our anatomy and physiology.
Regardless of whether Hollywood comprehends this physiology or not, it appreciates instinctively 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.