Fear is a fundamental part of the human experience, essential for survival. It alerts us to danger and prepares the body to react, either to fight or to flee.
While fear may seem boundless in its forms and triggers, research in developmental psychology suggests that humans are born with only two innate fears: the fear of heights and the fear of loud noises.
These are present from birth or very early infancy. All other fears, from fear of the dark to social anxieties, are acquired through environmental exposure, learning, and personal experience.
Fear of Heights
The fear of heights is deeply rooted in our evolutionary biology. Though newborns may not immediately display a reaction to heights.
Studies such as the famous "visual cliff" experiment show that infants as young as six months old hesitate to crawl over a transparent surface that appears to drop off sharply.
This suggests an inherent wariness of falling, likely an adaptive trait passed down through evolution. Avoiding steep drops or high places would have increased the chances of survival for early humans, and this caution has been hardwired into our instincts.
Importantly, this fear does not require a traumatic fall or a parent’s warning. It emerges even in infants who have never been exposed to dangerous heights. This highlights its innate nature—an inbuilt response to a potentially fatal threat.
Fear of Loud Noises
The second universal fear observed in newborns is the fear of loud noises. Known as the Moro reflex, babies exhibit an involuntary startle reaction, throwing out their arms and legs, when they hear a sudden, loud sound.
This reflex is part of the nervous system’s natural response to unexpected auditory stimuli. Loud noises may signal danger in the natural world, thunder, predator growls, explosions, or other disruptive events.
The fear of loud noises thus serves a protective function by immediately alerting an infant to something that may pose harm. Like the fear of heights, this fear is not taught but appears in early infancy, regardless of cultural background or environment.
The Rest of Fears Are Learned
While these two fears are innate, virtually every other fear is acquired. As children grow, they begin to observe, imitate, and internalize responses to the world around them.
A child might develop a fear of dogs after being bitten, or simply after seeing a parent scream in fear when a dog approaches. This type of learning is known as observational learning, where behavior is shaped by watching others.
Fear can also be learned through direct experience. A traumatic event, such as getting lost in a crowded place, can leave a lasting impression and lead to future anxiety in similar environments.
Similarly, negative reinforcement, like being reprimanded in school, might cause a child to associate fear with academic settings or authority figures.
Even societal and cultural influences play a major role. Media coverage of plane crashes, for instance, may instill a fear of flying in someone who has never set foot on an airplane.
Stories, superstitions, and even the way adults talk about certain situations can deeply influence how fears develop in individuals over time.
Brain’s Role in Fear Development
The human brain is designed to learn quickly from threatening experiences. The amygdala, a small structure in the brain involved in processing emotions, plays a critical role in fear responses.
When faced with a potential threat, the amygdala triggers a cascade of reactions in the body, preparing it for action. Over time, the brain connects certain stimuli with negative outcomes, strengthening neural pathways that associate fear with specific events or objects.
This is why phobias can be so deeply ingrained, even when they're irrational. The brain doesn’t always distinguish between real and perceived threats, especially once a fear has been established.
Fortunately, through therapies such as cognitive behavioral therapy (CBT), these learned fears can be gradually unlearned or managed.
