Most people have something they’re especially afraid of — perhaps spiders, which nearly 15% of Americans report fearing, or heights, which studies show affects roughly 1 in 5 people. But what exactly causes people to develop phobias?

Phobias vs. Reasonable Fears

First, it’s helpful to understand the distinction between a phobia and a natural fear of something genuinely dangerous. A phobia is an intense fear that is out of proportion to the actual risk posed by the object or situation and often interferes with daily life. As Ron Rapee, a professor of psychology and founding director of the Centre for Emotional Health at Macquarie University in Australia, puts it: “Most phobias share similar characteristics and differ only in what triggers the fear.”

Common symptoms of phobias include avoidance of the feared object or situation, anxious thoughts, and physical responses such as increased heart rate or rapid breathing. Unlike healthy caution, which can be useful in genuinely risky situations, phobias tend to amplify fear beyond what the situation warrants.

The Evolutionary Roots of Phobias

Some phobias, like a fear of heights or snakes, may have evolutionary origins. Rapee notes, “In most cases, phobias are related to realistic, evolutionarily sensible threats.” For example, while we rarely encounter phobias of electrical outlets (which can be dangerous), we often see fears of things like storms, spiders, or predators, all of which posed significant threats to survival for early humans.

Yet, not everyone develops phobias. Why do certain people experience an intense, disproportionate fear, while others don’t?

Learning and Environment: The Role of Childhood

One explanation is that phobias are “learned” early in life. This could happen directly, through a bad experience like being bitten by a dog, or indirectly, by observing someone else’s fear response. For instance, a child who repeatedly hears warnings about the ocean or sees frightening images in movies like Jaws or Titanic might develop a fear of large bodies of water (thalassophobia).

However, negative experiences aren’t always necessary. Many psychologists suggest that our experiences or even cultural influences can cluster around certain fears, causing them to become more common.

The Case for Inborn Fears

There is also a theory, called the "nonassociative account," which suggests that some fears may be innate and not necessarily learned. According to Chris Askew, a psychology lecturer at the University of Surrey, this theory proposes that people might be genetically predisposed to fear certain things without having had any negative experiences with them. While this idea remains debated, it’s likely that a combination of genetic and environmental factors contributes to why some individuals develop phobias while others don’t.

Personality Traits and Genetic Predisposition

Certain personality traits, such as neuroticism or behavioral inhibition (a tendency to react strongly to new situations), are also associated with a higher risk of phobia development. People who are temperamentally fearful and emotional, for example, are statistically more likely to develop phobias, particularly those related to natural elements like water or heights.

Research even suggests that phobias and anxiety disorders may run in families, likely due to both genetics and the “shared family environment.” Family members who model avoidance behaviors, for example, may unintentionally teach children to fear the same things.

Why Phobias Persist — And How to Overcome Them

Phobias can last a long time, partly because people tend to avoid what they fear. Rapee explains, “Avoidance reinforces phobias because it prevents people from facing the feared object or situation and realizing it may not be as dangerous as they think.”

For those seeking to overcome a phobia, exposure therapy can be a powerful tool. In exposure therapy, people gradually confront the feared object or situation in a safe, controlled environment. This systematic approach helps them learn that their fear is disproportionate and that the feared consequence is unlikely to occur. When exposure therapy is consistent, some studies even show that people can make significant progress in a single session.

As psychologist Kelvin Wong notes, “The goal is for the patient to gradually approach their phobic stimulus in order to learn that what they fear will not come to pass.”

In short, while phobias can seem deeply ingrained, understanding their roots and engaging in structured exposure can help people reclaim a sense of control, breaking free from these intense fears.

Sources:
https://my.clevelandclinic.org/health/diseases/21852-arachnophobia-fear-of-spiders
https://doi.org/10.1016/S0005-7967(98)00015-1
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5573560/

Discover