Animal phobias are likely the most common type of phobias, followed by an extreme fear of heights.

Fearology, or the study of fear, explores the difference between stress and fear

Our brains involuntarily respond to our environment and signal alarm when that isn't always needed, triggering responses that include goose bumps. But understanding fear and how to talk our brains into calming down can improve daily life.

An intense fear must persist for at least six months to be diagnosed as a phobia.

Lesser-known phobias include turophobia, or the fear of cheese, and nomophobia, the fear of being without your cell phone.

Unlike milder fears, phobias may get in the way of proceeding with your life.

Brain conditions and surgery can cause some individuals to feel no fear

Fear is a survival mechanism that originates in the brain's amygdala, triggering the body's fight-or-flight response. However, in modern society, without the same natural dangers, fear can lead to anxiety and mental health issues when unnecessarily triggered. Understanding individuals without fear may help identify new methods to treat anxiety disorders.

Fear or disgust related to clusters of holes and cracks, called trypophobia, may stem from evolutionary processes to help us avoid pathogens.

Why does the body have a stress response?

When encountering a stressful situation, the human body typically goes into what is known as "fight-or-flight" mode. Because it evolved as a survival mechanism, the biochemical response enables people and other mammals to react quickly to life-threatening situations. The carefully orchestrated yet near-instantaneous sequence of hormonal changes and physiological responses helps someone to fight the threat off or flee to safety.

Why are humans hooked on horror?

A haunted horror attraction in Denmark is regularly stalked by researchers of the world's only laboratory dedicated to understanding fear's good side. Fear is one of many human emotions that correspond to a physiological response. As fear rises, so do adrenaline, cortisol, and heart and breath rates. As it ebbs, the body is flooded with dopamine, a hormone and neurotransmitter associated with desire, learning, and motivation.

The science of fear

The Hidden Brain podcast team explores the science of fear by traveling to a haunted house curated by a scientist to investigate what scares us, and why some people enjoy this sensation more than others.

Our ancient fight-or-flight response may contribute to modern ailments

Many common modern diseases humans struggle with may in fact have their origins in our ancient fight-or-flight stress response. Long-term effects of the stress hormones cortisol and adrenaline—in this case, triggered by things like workplace stressors—can wreak havoc on the delicate internal balance of our organ systems.

See 16 art pieces that were inspired by or evoke elements of top phobias.

Fear (and stress) can be contagious via pheromones secreted by the body

While seeing someone else in a panicked state may induce a stress response, researchers have found stress can be literally contagious—chemicals contained in sweat and other secretions can trigger stress hormone release in others. Theories suggest this feature is an evolutionary adaptation to protect groups from danger.

Apeirophobia is the fear of everlasting life and may stem from the human brain's inability to conceptualize the concept of anything happening beyond what it can project out, such as the concept of an infinite life.

Why some people have allergies

Why do some people have allergies while others don’t? One theory suggests allergies are a relic of our evolutionary past. Our immune system, once primed to fight parasites, now mistakes harmless substances for threats.

Why so many people love roller coasters even though they’re scary

When a threat arises, it triggers our bodies to go into fight-or-flight mode and prepare for danger. However, when no obvious threat to our safety is present, this natural high can become enjoyable. Some people are more likely to enjoy these thrills based on factors like individual brain chemistry or physical health.

Stress activates the "fight-or-flight" response when we face threats, a reaction that can help keep us alive.

Fear has a specific 'smell'—at least to machines

This excerpt from a Mythbusters episode takes on the smell-of-fear question, comparing the sweat composition of individuals exposed to snakes, rats, and scorpions with that of people exercising. Molecularly, the sweats are different to a gas chromatography machine, but to most noses would be indistinguishable.

There’s a psychological explanation for ‘FOMO,’ or the fear of missing out

This video breaks down FOMO—what it is, how it works, and why it happens—showing how social comparison and uncertainty trigger anxiety that pushes people toward risk-taking and constant checking behaviors.

Some researchers have labeled nomophobia, the fear of being without your phone, as 'the phobia of the 21st century.'

How the feared self fuels OCD

Obsessive-compulsive disorder is characterized by intrusive thoughts that prompt people to enact compulsions—behaviors intended to relieve the anxiety or stress from the obsession. A significant intrusive thought OCD sufferers endure is the fear they will become a dangerous or immoral person. Therapeutic approaches try to show patients this is just a story that can be set aside.

Panic attacks are intense fear episodes that often occur without a clear trigger

Unlike typical fear responses to real danger, panic attacks can mimic serious health problems, such as heart attacks. Sweating during a panic attack may seem random, but it's a leftover survival mechanism that made it easier for our ancestors to escape by slipping out of an attacker’s grasp.

Why we pay to be scared

Why do we love roller coasters? It’s not just the speed or height, it’s controlled fear. Your brain thinks you’re in danger, then rewards you with dopamine.

Goose bumps are often triggered by emotions

A physiologist and professor of zoology explains that the subconscious release of adrenaline, a stress hormone, causes a contraction of skin muscles. It’s released in several situations, including when humans are cold, afraid, or feel strong emotions. (Some readers may experience a paywall.)

The hormone that spreads love and helps fish share fear

Scientists consider emotions like fear and empathy to be among the oldest evolutionary behaviors observed in mammals. Yet to date, how these reactions are processed in the brain, regardless of species, is not well understood. A new study reveals how the chemical oxytocin—known as the "love hormone" in humans—helps let fish know when their friends are in danger.

Researchers say that the horror genre offers opportunities to safely experiment with fear.

Stress-induced adrenaline can trigger a 'hysterical strength' response

The stress response is a powerful ancient mechanism designed to maximize human survival—it can even result in superhuman strength. The adrenal glands are located just above the kidneys, and stress-induced adrenaline release causes more blood (and therefore more oxygen) to flow to your muscles, increasing performance.

Misophonia is a neurological disorder where sounds trigger strong emotions

The phenomenon is characterized by decreased tolerance to specific sounds, such as heavy breathing, pen clicking, and water dripping, which trigger a fight-or-flight response. The resulting emotions, which can range from irritation and disgust to anxiety and fear, can be overwhelming and uncontrollable.

The science of food allergies

Why do certain substances trigger an immune response while others don't? Listen to researchers explain the science in this five-minute video. Food allergies affect around 8% of children and 2% of adults in the US, and—unlike sensitivity or intolerance—they involve the immune system mistaking certain harmless proteins in foods as dangerous invaders, triggering a rapid and sometimes severe defense response.

The biology of stress in your body

Stress is a normal human response that has evolved over millions of years to handle changes or threats in our environment. This article is a helpful overview of the biological basics of this response. While it is not harmful to our physiology in the acute setting, chronic stress can lead to damaging changes in the human body over many years.

What do your dreams mean, according to science

Humans have been interpreting dreams as signs from deities, spirits, or the psyche for ages, and research shows that reflecting on and analyzing one's dreams can be beneficial. In alignment with dreams' elusive nature, they have no objective or clearly assigned meaning. However, variations of common dreams, such as a surprise exam in a forgotten class, are rife with shared primal fears.

Charles Darwin studied goose bumps by scaring zoo animals in London with a stuffed snake

Read the famous naturalist’s work from the late 1800s, detailing how he sought to draw comparisons between how animals and humans respond to fear. As part of that work, he exposed monkeys and a peccary to a stuffed snake and noted the animals’ hair-raising fear response.

Fevers are an immune response to create hurdles for pathogens

Substances called pyrogens prompt the brain to raise the body temperature to levels where bacteria and viruses struggle to survive. The higher temps also support immune cells fighting off the invaders.

Can physics explain where consciousness comes from?

Consciousness is a complex emergent phenomenon of the brain, which is primarily composed of neurons and glial cells. Since all matter is composed of atoms that follow the laws of physics, there may be quantum processes beyond classical electrochemical interactions that can explain where consciousness comes from.

When common sounds become disturbing

Misophonia causes certain sounds to feel violating, triggering a "very visceral kind of experience" filled with extremely unpleasant emotions, including annoyance, anger, and disgust. A 2017 study found that people with misophonia have elevated activity in the brain's anterior insula—a region associated with interoception, emotional processing, and behavioral responses—when exposed to trigger sounds. Ongoing research suggests trigger sound context affects the severity and manifestation of the condition.

Some theorize that horror's artifice turns fear into enjoyment

The “excitation transfer theory” suggests that the unpleasant feelings a jump scare might elicit (like shortness of breath) are quickly relieved when the audience member remembers what they’re witnessing is fake.