Clusters of holes trigger intense disgust in many people. Evolutionary origin theories exist but the specific neural pathway remains unidentified.
Peripitus, CC BY-SA 4.0, via Wikimedia Commons
An Overgeneralized Survival Instinct
The intense, skin-crawling aversion to clusters of small holes, known as trypophobia, affects a significant portion of the population. A 2013 study by researchers Geoff Cole and Arnold Wilkins reported that about 16% of participants felt discomfort or repulsion when viewing an image of a lotus seed pod. Subsequent research suggests the prevalence might be between 10% and 18% of adults. This response is not limited to holes; clusters of bumps can also trigger the same feelings of disgust and nausea.
While widely documented online, trypophobia is not recognized as a distinct disorder in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM-5). The primary emotional reaction for most sufferers is disgust rather than fear, which complicates its classification as a specific phobia. The term itself originated on an internet forum in 2005. Despite its unofficial status, the physiological reactions are measurable; looking at triggering images can cause an increase in heart rate and heightened activity in the brain's visual processing areas.
Ancient Dangers in Modern Patterns
The leading explanations for trypophobia are from evolutionary psychology. One theory proposes that the aversion is a misfiring of an ancient mechanism for avoiding dangerous animals. Cole and Wilkins discovered that many venomous creatures, such as the blue-ringed octopus, deathstalker scorpion, and certain snakes, have patterns on their skin that share specific visual characteristics with trypophobic images. These characteristics involve high-contrast energy at midrange spatial frequencies, a type of visual information the brain can process rapidly and nonconsciously. The response is an overgeneralized survival instinct, where the brain flags a harmless visual pattern because it resembles a potential threat.
A competing, and strongly supported, theory suggests the response is an overgeneralized disease-avoidance mechanism. Many infectious diseases and parasitic infestations, like smallpox or measles, manifest as rashes or lesions that form clusters on the skin. The disgust reaction prompted by trypophobic patterns is like the disgust we feel toward signs of illness. Studies have shown that when cluster patterns are photoshopped onto human skin, the level of revulsion increases significantly. This suggests the brain may be hardwired to react negatively to patterns that signal contamination or sickness, an instinct that would have provided a clear survival advantage.
💡Fun Facts
The term "trypophobia" was first used by an anonymous user in an online forum in 2005.
Researchers found that many poisonous animals, including the blue-ringed octopus and king cobra, have markings with the same visual properties that trigger trypophobia.
Even people who do not identify as trypophobic often rate images of clustered holes as more uncomfortable to look at than neutral images.
Studies have found associations between trypophobia and other conditions, including major depressive disorder and generalized anxiety disorder.
