A cloud resembling an angel reassures some and terrifies others. Traffic jams stretch for blocks as people flock to see the Virgin Mary on a bathroom window. Photos of Martian rocks resembling people, rats, and crabs go viral in an instant. People see ghosts and spirits on misty mornings.
That’s the power of pareidolia, a peculiar, but entirely natural, function of the human brain that causes us to impose patterns on random collections of images and sounds. From the Greek para (“alongside of, instead of”) and eidolon (“image, shape”), pareidolia is an ancient ability that may have helped us survive in the far distant past, back when we needed to be able to pick out hidden dangers in the landscape.
Notably, Carl Sagan made this claim in 1995 in his book The Demon-Haunted World: Science as a Candle in the Dark, asserting that it is a phenomenon that results from how our brains interpret light and shadows (sometimes drawing meaning from these features when there is none).
Pareidolia accounts for ancient tales of tree-dwelling dryads, trolls who guard gardens and bridges, and stone giants. It’s what lets us see shapes in the contours of clouds, find a face on the surface of the Moon, and trace the constellations in the night sky. And while the phenomenon has been in existence for all of our history, it has made the transition from psychology textbooks to the popular imagination in recent years, thanks to media attention.
Pareidolia explains the famous Virgin Mary on a cheese sandwich that sold on eBay for $28,000, the cornflake shaped like the state of Illinois that was auctioned off for $1,350, and even the much-revered Shroud of Turin, which many observers believe reflects the figure of a crucified Jesus Christ.
We have countless reports of religious figures seen in peculiar places and a constant stream of photographs sent by the Curiosity Rover from the surface of Mars to inspire our imaginations, but interestingly, not everyone experiences pareidolia in the same way — or at all — and it seems to be influenced by culture.
Psychologists note that people with strong beliefs in religion or the paranormal are more likely to see meaning in random data. That accounts for the large number of instances of pareidolia involving religious symbols or figures. These range from that aforementioned Shroud to sightings of the Hindu monkey god in a Singapore tree to some claiming to see the name of Allah in photographs of the 2004 tsunami in Asia.
Even if many people see the same image, they may interpret it differently. The man that children in western cultures see in the Moon is the Moon Rabbit in Asia. In various other cultures, the same image is known as the Moon Buffalo, Dragon, or Frog. You may see a different shape in the fluffy cloud scudding overhead than your friend, or they might not see any recognizable shape at all.
Pareidolia isn’t limited to seeing, either. Auditory pareidolia refers to the phenomenon of finding meaning in random sounds, such as the electronic voice phenomena that ghost hunters claim is evidence of spirits speaking from beyond the grave. It also accounts for the rumored hidden messages in rock and pop music albums, like the belief among Beatles fans that certain tracks played backwards revealed the words “Paul is dead.”
It may seem that pareidolia leads only to silly and sometimes creepy outcomes, but psychologists exploit the phenomenon through tests like the Rorschach inkblots, where the shapes seen in random ink spatters are thought to reveal insights into a subject’s subconscious. Artists also play with pareidolia, creating images that can be seen in various ways. Georgia O’Keeffe’s flower paintings, for example, outrage some viewers — and delight others — who see in them suggestions of female genitalia.
The human brain’s tendency toward pareidolia hasn’t changed in thousands of years. It’s even migrated to the digital world in the form of facial recognition and mapping software. And even computer brains can be fooled by what they see, finding human faces on everything from keys to garage doors and rock formations, just as the ancient humans did. Ultimately, this confirms that you can’t believe everything you see (or hear) and should question absolutely everything.