The Science Behind Fear

By October 29, 2015 December 17th, 2019 Science of Color & Design, Visual Communication
Science Behind Fear Killer Infographics

Halloween is traditionally associated with scary things: ghosts, witches, horror movies, and more. Over the years, trends in costumes have introduced a few other adjectives beyond “scary,” like funny, hokey, and scandalous — and while we love a good joke costume as much as the next company, it’s time to put the fear back into Halloween. So what is fear, what does it do to us, and how do our bodies and minds react to being scared?

Where Does Fear Come From?

The human brain has a fear center: our amygdala. A feature we share with other mammals, reptiles, and birds, the amygdala portion of the brain is actually made up of 2 small almond-shaped clusters of neurons. Fear isn’t the only thing the amygdala controls, though — it’s responsible for perceiving all our emotions, and is one of the first parts of our minds to react to any situation.

Science Behind Fear Killer Infographics

Fear vs. Phobia

Fear is an emotional response to a threat, whether perceived or real. Almost everyone experiences fear, but there are exceptions: one woman’s rare disease actually calcified her amygdala, preventing her from feeling afraid.

A phobia is a fear that elicits such strong anxiety that it affects your quality of life and your ability to function — even though you’re actually aware you’re reacting unreasonably. The median age for developing a phobia is 7 years old, and it may stem from a traumatic experience or unexpectedly. According to the Anxiety and Depression Society of America, about 19 million Americans (8.7% of the U.S. population) have phobias; women are 2x more likely to have them.

Science of Fear Killer Infographics

While fear is a reaction, phobias seem to require a bit of processing time to take effect. A 2004 study, conducted by researchers at Karolinska Institute in Sweden , tested the amygdala’s reaction to general threats versus phobias by showing neutral images along with images of a variety of potentially threatening things (snakes, spiders) to participants with phobias of any of those things.

First, the scientists showed all the images too quickly for the subjects to know what they’d seen. Each subject’s amygdala reacted to every threatening image, whether or not they had a phobia related to it. But when the subjects had enough time to really see each image, their amygdalae didn’t react to most of them — except the ones displaying the target of their phobias. While the amygdala is responsible for much of our fear, other parts of the brain come into play to help distinguish reasonable and unreasonable fears.

Scared of Public Speaking? You’re Not Alone

Of the most common phobias, what are we most afraid of? Respondents in a 2014 study indicated they were afraid or very afraid of a wide variety of situations:

Science Behind Fear Killer Infographics

Fear and Memory

When we’re afraid, we release high levels of the stress hormone cortisol. According to secondary research by the Centre for Educational Research and Innovation, at low and medium levels cortisol can actually improve our ability to learn and retain information. However, at the high levels that fear induces, it’s believed to have the opposite effect — and can even contribute to memory impairment. That means it’s possible that too much fear could make you forget!

In traumatic instances of excessive fear or stress, such as war, abuse, or disaster, significant memory impairments like dissociative amnesia can occur. It’s often a symptom of Post-Traumatic Stress Disorder, and results in (usually traumatic) memories being deeply buried in the mind. Those memories may resurface on their own, or an outside influence may trigger the affected person into remembering.

Researchers are debating about the validity of these recovered memories — are they real memories, or constructed? Psychology Today says that 60-80% of those who practice, but don’t typically conduct research (clinicians, psychoanalysts, and therapists) feel therapy-based recovery of traumatic memories can be frequent and authentic, but under 30% of research-oriented psychologists agree.

Science Behind Fear Killer Infographics

AAAAHHHHH! What’s in a Scream?

The human scream embodies fear in 2 different ways: being afraid may make us scream, and hearing screams may make us afraid. Scientists discovered that fearful human screams trigger our amygdala (see the first section of this post: it’s the brain’s fear center). In fact, screams trigger it more than most other sounds — the only ones that create a similar response are car or house alarms and emergency vehicle sirens. All these sounds spur a cautionary or alarmed reaction (fear) instead of an inquisitive or analytic one. Part of this is because of the rapid rate of volume change in these sounds, known as “roughness.”

Normal speech fluctuates 4-5x per second, while a scream fluctuates 30-150x per second. This is so fast that we don’t perceive the rise and fall of volume, but register the sound as being unpleasant — and the rougher the scream or alarm, the scarier it was ranked by volunteers in the study. It’s worth noting that the study only covered screams recorded with the emotion of fear in mind — screams of joy and heavy-metal screams, for example, have different roughnesses and other vocal traits that probably don’t impact the amygdala in the same way.

Science Behind Fear Killer Infographics

Even Your Skin Reacts to Being Scared

Our skin’s moisture content can increase for any number of reasons, including a room’s temperature and humidity, but it’s also an indication of fear. When we’re stressed, our nervous systems trigger a release of moisture that collects under our skin, increasing skin’s electrical conductivity. Game developers testing fear response in Until Dawn, a horror-themed video game, used technology from MIT — Galvanic Skin Response Testing — to measure skin’s moisture content while playing the game. This helped tell them which experiences were scary and which needed to be revisited. Of course, the room’s temperature and humidity came into play, but it was a unique and scientific way to try to measure the fear factor.

The Genetics of Fear

Can fear be inherited? It sounds far-fetched, but according to science, there may be a link — in one study, researchers exposed mice to a scented compound and simultaneously administered shocks to create an association between the smell and pain. Next, they mated the mice and introduced the scent — but no shock — to their offspring. Compared to a control group, the offspring of the shocked mice had stronger negative reactions (restlessness, fear) to the scent, indicating that significant fears might be passable to other generations.

Give in to fear this Halloween — that cat costume can wait until next year.

Lucy Todd

Author Lucy Todd

Lucy Todd is the Chief Process Officer at Killer Visual Strategies. She is a Seattle native and Western Washington University graduate. Her degree in Creative Writing and her customer service background both inform her work daily. A Killer employee since 2011 and executive since 2014, Lucy has researched for, written, and/or project-managed over 4,000 projects for the company, affording her key insight into our processes and projects. This experience is invaluable in allowing her to lead and empower Killer’s content and project management teams to success. Lucy enjoys managing the day-to-day at the office, offering a unique perspective when a team or colleague feels stuck, and learning from her peers and clients each day.

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Join the discussion 2 Comments

  • Lily Styers says:

    Heyo! I have been researching fears/phobias/ irrational fear in general to do a TED talk to my peers in our 8th grade gifted and talented program. I am not much of a public speaker (to say the least; I’ve nearly fainted. Call it MY phobia) and I was hoping that to lengthen the time of my talk, I could put in a video on the science of fear. My teacher, who is ahead of me on this one, has put a one-to-two minute restriction on the length of the video. I can’t find a video that is scientific at ALL that fits the time period. Do you know of any?

    • Lucy Weiland says:

      Hi Lily! We found some great videos that are a little longer than the length requirement for your class, but you can select the most impactful 1-2 minutes out of the videos to show! Here’s a video that’s you could move up to around 43 seconds and start from there — this gives an example and then explains the science of how the fear is transmitted, delivered by an associate professor of psychology at Georgetown. Here’s another that might be helpful, talking about the physical danger of fear. Just remember to write down the starting point of the information that you find most helpful, so you can be sure to fit the critical information within your teacher’s length requirement.

      I hope this helps!

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