Why Your Hearing Has a Built-In Fear Response
What do the top horror movies all have in common?
They all have memorable soundtracks that arouse an instantaneous sense of fear. As a matter of fact, if you watch the films without any sound, they become a great deal less scary.
But what is it about the music that renders it frightening? More specifically, if sounds are simply vibrations in the air, what is it about our biology that makes us respond with fear?
The Fear Response
In terms of evolutionary biology, there’s an obvious survival advantage to the instantaneous acknowledgment of a harmful situation.
Thinking is time consuming, 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 deliberately.
Given that it takes longer to process and contemplate visual information, the animal brain is wired to react to faster sound-processing mechanisms—a trait that provides survival advantage and has been selected for in the wild.
And that’s precisely what we see in nature: several vertebrates—humans included—generate and react to harsh, nonlinear sounds and vocalizations when alarmed. This creates a nearly instant feeling of fear or anxiety.
But what is it about nonlinear sound that makes it scary?
When an animal screams, it produces a scratchy, irregular sound that extends the capacity of the vocal cords beyond their typical range.
Our brains have evolved to recognize the properties of nonlinear sound as abnormal and suggestive of dangerous situations.
The interesting thing is, we can artificially simulate a variety 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 produce scarier films.
Music and Fear
We all are familiar with the shower scene from the classic movie Psycho, and it’s probably one of the most terrifying scenes in the history of cinema.
But if you view the scene without sound, it loses the majority 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 fully engaged.
To confirm our natural aversion to this nonlinear sound, UCLA evolutionary biologist Daniel Blumstein conducted a study examining the emotional reactions to two types of music.
Participants in the study listened to a collection of emotionally neutral scores and scores that incorporated nonlinear elements.
As anticipated, 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.
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 audience.
Want to see the fear response in action?
Listen to these 10 Essential Horror Movie Scores.