From an evolutionary perspective, our fear instincts make a lot of sense. But in our cozy modern-day lives, fear sometimes seems to do more harm than good.
A tiny jumping spider which, though it produces venom, is harmless to humans. Photo by Gido/Flickr
When I was three years old I fell into a fire. We were having a family bonfire in the backyard and as I went toddling towards the flames, blankie in hand, I stumbled at the last second and fell face-first.
My Dad scooped me up, rushed me to the house, and doused me in the nearest sink. It turns out my blanket had smothered the fire, and I was physically unharmed—not even a skiff of a burn. But my parents' panic, the running, the being dunked in freezing cold water left a mental scar. I was terrified of fire for a long time after.
It's not all that irrational to be afraid of fire, but I was scared of any kind of flame. Candles disturbed me. Campfire sparks made me jump with panic. I couldn't light a match until a few years ago, and I still struggle with lighters.
From an evolutionary perspective, our fear instincts make a lot of sense. They're a method of threat detection, allowing us to identify and react to the poisonous snakes and the hungry bears and the dozens of other death-mongers that surrounded humans when we lived outdoors. But in our cozy modern-day lives, fear sometimes seems to do more harm than good. My fear of lighting matches wasn't protecting me from harm, it was just preventing me from earning my fire-building badge in Cub Scouts—and I'm not the only one who has suffered from useless fears.
"We're, in some ways, in the midst of a fear and anxiety epidemic," Justin Feinstein, a clinical neuropsychologist at the Laureate Institute for Brain Research, told me over the phone. "You'd think with all of our amenities and safety and luxury we would be relaxed, but it doesn't seem to be the case for a lot of people."
Instead of living a glorious, post-fear existence in the comfort of our sheltered lives, needless fears plague us. Meanwhile more useful fears—like being frightened of texting and driving—refuse to take root. What role does fear have in a world where we're usually pretty safe? And why, exactly, are we still so afraid?
This Is Your Brain on Fear
When a human encounters a fear stimulus, a series of lightning-fast reactions are set off in the brain, according to Nouchine Hadjikhani, a Harvard university neuroscientist who studies a wide breadth of brain functions, including emotional perception. It's so fast and instinctive, it can even happen subliminally, without us ever consciously realizing we've encountered a fear stimulus at all, Hadjikhani told me.
Let's say you're walking in the woods and a snake emerges from the grass. In a fraction of a second, the snake is recognized as a threat by the subcortical system, the part of the brain responsible for innate life-sustaining functions like breathing and heart rate, Hadjikhani said. Here's how it all breaks down, according to Hadjikhani:
- The retina sends information to the superior colliculus, then to a part of the thalamus called the pulvinar. (Time: less than 100 milliseconds)
- The pulvinar alerts the amygdala (often dubbed the brain's "fear center"), and together they rope in the visual cortex. (Time: 20 milliseconds.)
- The visual cortex analyzes the information, sends it back down to the pulvinar and amygdala, and also to the frontal cortex. (Time: less than 100 milliseconds.)
Total time: 200 milliseconds or 0.2 seconds
"And all of this goes down to trigger reactions in the body," Hadjikhani said.
You should be familiar with these reactions: adrenaline, alertness, a racing heart, a tight stomach. Fear. Those physical reactions cause other parts of your brain to take notice—something's happening—including the insular cortex, which is responsible for self-awareness, perception, and motor control. It's not until this point (about half a second after you first laid eyes on the snake) that you actually become consciously aware that there is a snake, Hadjikhani said.
Our fear system evolved to be efficient and effective to keep us safe. If that snake was poisonous, we might not have more than a second or two to react before getting bitten. We don't necessarily need to have these lightning-fast reflexes in most situations that spook us now, at least in the western world. But we haven't evolved away from it because, well, evolution takes a really, really long time.
"It takes time to evolve and you can't control it," Hadjikhani told me. "You can train people to get rid of some fears, but you can't control the first reaction. The first reaction will always be there. This is part of our hardware."
The Birth of Fright
My fear of flames followed a classic pattern, from its inception to the point when I (more or less) overcame it, according to Dean Burnett, a neuroscientist at Cardiff University who is currently writing a book on the brain's more confounding functions, like fears, beliefs, and superstitions. He noted that this is the best information he has on the subject, but our understanding of fear is still evolving.
While our fear reaction system is innate, the things that stimulate that system—the things we fear—are learned. No one is born afraid of spiders, though humans are predisposed to developing a handful of common fears, Burnett said. Babies are naturally adept at identifying snakes, for example, but they don't react with fear until later in life, when they've learned that snakes are something not just to notice, but to be frightened of. This can be learned a number of ways, like having a negative encounter with the fear stimuli.
"If you're a child and a clown approaches you and gets right in your face, that can be a scary experience," Burnett said, (sounding suspiciously as though he was speaking from experience). "It is scary to have this massive, white-faced stranger with a huge, big smile just bearing down on you. It's quite unsettling for a child who has no experience of this."
That experience of an unknown, disturbing stimulus can cause an initial fright response, which then gets lodged in your reference system, Burnett said. Next time you encounter that stimulus, even if this new clown isn't so aggressive, your brain pulls out that first memory and fires up a similar response.
"The memory is very vivid because if you experienced something bad, you don't want to experience it again, so you don't want to forget it," Burnett said. "The memory system really kicks it up a gear to make sure that this bad thing isn't lost."
As children we also pick up cues from the adults around us, which can feed a lot of our fears, Burnett said. You might find mice perfectly fascinating as a child until you see an adult screaming and hopping on a chair at the sight of one. And falling face-first into a fire might not actually be that scary if you don't get burnt, until your parents start losing their shit.
We don't only fear physical threats, either, Burnett said. Our brain evolved to detect physical threats to keep us safe, but it's not able to quickly distinguish between physical threats and other negative experiences.
"Social threats like embarrassment, or shame, or guilt, or the judgement of others, these are also labelled at threats because our brain is still operating on principles that developed over millions of years," Burnett told me. "Human society has only been around for a few thousand years. The dangers we evolved to avoid are more or less gone now, but the mechanisms to detect them are still active."
This all adds up to a human brain that can potentially fear any stimuli (which is how some people develop unusual phobias) and fears that are difficult to shake.
The most effective way to get over fears is by using our conscious mind to override our unconscious one, Burnett said. This can be done either by not letting the fear develop in the first place (getting back on a horse after your first fall so that the fall isn't the only memory associated with the experience) or through systematic desensitization (gradually reacquainting yourself with a fear stimuli until the neutral experiences override the initial negative one).
The latter is how I reduced my fear of flames: light a match enough times without anything bad happening and your brain will eventually let go of the connection. But there's a caveat.
"The fear reaction itself is a negative experience," Burnett said. "It becomes a sort of feedback loop. The brain's defense mechanism tricks itself by making non-dangerous things dangerous because they elicit this reaction."
A Life Without Fear
Some people are never afraid. Individuals who have damaged amygdalae don't experience a fear response to most stimuli. In fact, until 2013 it was widely believed that you couldn't feel fear without a fully-functioning amygdala. But that year, a study was published in Nature Neuroscience that showed individuals with damaged amygdalae became afraid and even had panic attacks when breathing air spiked with higher-than-normal levels of carbon dioxide. They can feel fear, but only through internal stimuli.
Feinstein, who was lead author of that study, has spent his entire career trying to scare the unscareable. He said he is fascinated by his subjects, who differ from your average person by not steering clear of situations that people with "normal" fear responses would avoid. One famous subject who is completely missing her amygdala—identified only by the initials S.M.—has gotten into multiple dicey situations due to her lack of fear.
"Everything from horror films to snakes and spiders to haunted houses fail to induce a fear response in her," Feinstein said. "Then when you look at her life history, what you see is a pattern of exposure to pretty severe traumatic events where her own life has been threatened with knives or guns or even worse. And a lot of these events happened because of her lack of fear."
Her risky behavior shows the benefits of fear, even in our normally comfy lives. Part of the reason they're so comfy may be the fact that we can feel fear in the first place. It's a constantly whirring mechanism quietly keeping us from harm, always on the alert for the next threat. And while our pre-wired, primal, ape brains are set up with systems that weren't optimized for our modern world, millennia of evolution favored instincts that kept us alive, and still do. But in the absence of real threats, our self-preservative responses are also triggered by a host of innocuous stimuli, and short of widespread amygdalectomies, there's nothing we can do to change that.
We have to live with our fear-disposed brains. But, as Burnett pointed out, we don't necessarily have to live with the fear.
"As a child, you're constantly learning and experiencing new things, and you get a more realistic world view and learn that things aren't frightening," Burnett said. "As an adult, if you continue experiencing and learning new things all the time, you can stop being afraid."
Correction: An early version of this story said individuals with damaged amygdalae were exposed to carbon monoxide to induce a fear response. They were exposed to carbon dioxide. Motherboard regrets the error.