What do the best horror movies all have in common?
They all have unforgettable soundtracks that bring about an instantaneous sensation of terror. In truth, if you watch the films without any sound, they become a lot less frightening.
But what is it regarding the music that makes it terrifying? More specifically, if sounds are just 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 instantaneous recognition of a risky situation.
Thinking is time consuming, especially 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.
Seeing that it takes a bit longer to process and think about 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 find in nature: numerous vertebrates—humans included—emit and react to harsh, nonlinear sounds and vocalizations when alarmed. This creates a virtually instantaneous sensation of fear or anxiety.
But what is it about nonlinear sound that makes it alarming?
When an animal screams, it creates a scratchy, irregular sound that stretches the capacity of the vocal cords beyond their typical range.
Our brains have evolved to recognize the qualities of nonlinear sound as unpleasant and suggestive of hazardous circumstances.
The intriguing thing is, we can artificially replicate a wide array of these nonlinear sounds to get the same immediate 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 films.
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 cinema.
But if you watch the scene without sound, it loses most of its impact. It’s only when you add back in the high-pitched screaming and bone-chilling staccato music that the fear response becomes fully engaged.
To reveal our natural aversion to this nonlinear sound, UCLA evolutionary biologist Daniel Blumstein carried out a study investigating the emotional responses to two types of music.
Participants in the study listened to a selection of emotionally neutral scores and scores that contained nonlinear elements.
As anticipated, the music with nonlinear elements aroused the most powerful 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 instinctively that the use of nonlinear disharmonious sound is still the most effective way to get a rise out of the viewers.
Want to witness the fear response in action?
Listen to these 10 Essential Horror Movie Scores.