What do the top rated horror movies all have in common?
They all have memorable soundtracks that bring about an immediate sensation of fear. In fact, 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 just 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 obvious survival advantage to the automatic recognition of a deadly scenario.
Thinking is time consuming, 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 consciously.
Given that it takes a bit longer to process and contemplate visual information, the animal brain is wired to respond to quicker sound-processing mechanisms—a characteristic that offers survival advantage and has been selected for in the wild.
And that’s precisely what we see in nature: several vertebrates—humans included—produce and react 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 alarming?
When an animal screams, it produces a scratchy, irregular sound that extends the capacity of the vocal cords past their normal range.
Our brains have evolved to distinguish the attributes of nonlinear sound as unpleasant and suggestive of life-threatening situations.
The interesting thing is, we can artificially simulate a wide array of these nonlinear sounds to get 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 are familiar with the shower scene from the classic movie Psycho, and it’s certainly one of the most frightening scenes in the history of film.
But if you view the scene without sound, it loses most of its impact. It’s only when you add 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 investigating the emotional responses 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 expected, the music with nonlinear elements aroused the most potent emotional responses and negative feelings. This response is simply an element of our anatomy and physiology.
Whether Hollywood understands this physiology or not, it knows intuitively that the use of nonlinear discordant sound is still the best way to get a rise out of the audience.
Want to observe the fear response in action?
Check out these 10 Essential Horror Movie Scores.