You may be, or have met, someone with an unlikely aversion to clusters and holes. The phobia, known as Trypophobia, is not officially recognized in the American Psychiatric Association’s Diagnostic and Statistical Manuel of Mental Disorders (DSM). Many people, however, report feeling an negative reaction or even fear of clusters of holes — such as those of a honeycomb, a lotus seed pod or even aerated chocolate.
"The phenomenon, which likely has an evolutionary basis, may be more common than we realise"
Stella Lourenco, psychologist at Emory University
Previous research linked trypophobic reactions to some of the same visual properties shared by images of evolutionarily threatening animals, such as snakes and spiders. The repeating high contrast pattern seen in clusters of holes, for example, is similar to the pattern on the skin of many snakes.
“We’re an incredibly visual species,” says Vladislav Ayzenberg, a graduate student in the Lourenco lab and lead author of the PeerJ study. “…visual properties can convey a lot of meaningful information [and] allow us to make immediate inferences — whether we see part of a snake in the grass or a whole snake — we react quickly to potential danger.”
However, further analysis revealed that perhaps trypophobic reactions weren't linked to the 'flight or fight' mode but instead something different. After tracking eye movement and pupil dilation, as well as body language, scientists surmised that clusters of holes may be evolutionarily indicative of contamination and disease — for example visual cues for rotten or mouldy food or skin marred by an infection.
So in fact, this seemingly random reaction to clusters, spots, and holes, is a feeling of disgust related to our evolutionary tendency to avoid infection or disease; just another example of our brain recognising pattern to decipher the world around us…