You’re all alone, walking home in the dark. It’s starting to get chilly, and a gust of wind makes you flinch and blows your coat around. Suddenly, you see something move out of the corner of your eye. Your heart starts beating furiously in your chest, you feel a chill run down your spine, and goosebumps cover your arms. You are afraid.
But what is fear, really? Like most emotions, it’s a combination of physical and emotional responses brought about by something perceived as a threat.
The physical part of fear starts in the section of the brain called the amygdala, the section of the brain dedicated to distinguishing when something has emotional significant. The amygdala then sends signals to the hypothalamus, which activates two systems in the body: the sympathetic nervous system and the adrenal-cortical system.
The sympathetic nervous system uses nerves to send signals and is what causes the body to tense up and become alert. It is also responsible for the release of the hormones adrenaline and noradrenaline, the ‘stress hormones’ that increase heart rate and blood pressure, preparing the body for the ‘fight or flight’ response to protect itself from the threat.
The adrenal-cortical system is activated by the release of corticotropin-releasing factor (CRF) into the pituitary gland, which then causes the secretion of adrenocorticotropic hormone (ACTH) into the bloodstream. ACTH then causes the release of around 30 different hormones into the bloodstream, all acting to prepare your body for whatever caused your fear.
Together, all of these stress hormones cause the body’s physical response to fear. As well as the increased heart rate and blood pressure to move blood around more quickly, they also cause pupil dilation, allowing for better vision, increased blood glucose levels to provide cells with energy, and the shutdown of ‘nonessential’ systems like the digestive and immune systems so that the body can focus entirely on the threat. The hormones also cause veins to constrict in order to send more blood to muscles so they can be used more easily, which is what causes the ‘chill’ you feel when afraid, and cause muscles to tense so they’re ready for use, which is what causes the tension on your skin that creates goosebumps. This prepares the body to respond to the threat, be it by fighting it off or escaping.
While fear isn’t a purely physical phenomenon, the emotional component of fear is more difficult to explain and study because it’s personal to each individual. Some people are adrenaline junkies, getting scared on purpose to feel the rush, while other people avoid feeling it at all costs. Fear can also have many different causes. It can come from being in danger, or feeling negative physical effects, or anticipating unpleasant events, or a wide variety of other things. Fear is generally learned through personal experience, but humans are special because we can learn fear through instruction from another.
Over time, the fear response becomes less and less powerful as a person becomes acclimatized to a specific stimulus. This is why thrill-seekers tend to look for more and more dangerous experiences and why exposure therapy for phobias is effective. This is because repeated exposure to stimuli makes it become familiar.
If you’re interested in testing your own fear response during this spooky season, you can check out haunted houses the 13th Floor Haunted House here in Columbus or Haunted Hoochie Dead Acres in Pataskala, or if you’re up for a little more travel you can check out the Halloween events on the weekends at Cedar Point or King’s Island.