Fear

I’m not afraid of getting Covid-19. This is partly because, knowing how the disease is contracted and that its prevalence is relatively low in my county, it’s unlikely that I’d get it. That’s my rational brain at work. My lack of fear also seems hard-wired. I can’t help it.

The degree to which we experience fear has a genetic component. Researchers have developed lines of mice in which all members are fearful. A newborn mouse from a fearful line who is reared by a fearless step-mother will still be fearful as an adult. Studies of adopted children as well as identical and fraternal twins reared either together or apart have also shown that fearfulness has a clear genetic component.

Multiple genes and multiple processes are involved in fearful responses. For one thing, if you lack functional nerve cell receptors for a certain chemical (gamma-amino butyric acid), you will be more fearful. That’s because the higher regions of our brains use the chemical to tone down our lower brain’s initial impulses, which could result in an overly fearful response to stimuli. (The “lower brain" is the amygdala and is involved in fight or flight impulses.) Genes also affect our bodies’ uses of serotonin, which regulates anxiety, as well as stress hormones.

Some researchers have figured out a treatment to lessen the power of fear. It’s called “eye movement desensitization and reprocessing” (EMDR). Therapists use it to treat PTSD and other fear-related problems. The technique includes having patients move their eyes in specific ways while either recalling traumatic events or being exposed to a fear stimulus. Scientists don’t know exactly how it works, but it has to do with tamping down the amygdala’s fear response while activating brain pathways involved in controlling emotion. Researchers can test the efficacy of these methods using fMRI scans and by measuring electrical skin conductance, which is a measure of fear. The methods seem to work.

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