In Brief
Pareidolia is responsible for the Man in the Moon and any other peculiar faces you may see in random clusters of objects. The human brain may have evolved to look for these patterns in order to spot hidden threats.

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.

mars
A happy face on Mars. Image credit: NASA

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,” it’s an ancient ability that may have benefited survival in the far distant past when it was essential to pick out hidden dangers in the landscape. Notably, Carl Sagan made this claim in his 1995 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 making meaning from these features when there is none).

Familiar Shapes in Strange Places

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 that’s been in existence for all of our history, pareidolia has gone from psychology textbooks to the popular imagination in recent years, thanks to media attention. 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.

Pareidolia explains the famous Virgin Mary on a cheese sandwich, which sold on eBay for $28,000, the cornflake shaped like the state of Illinois auctioned off for $1350, and even the much-revered Shroud of Turin, which to many observers reflects the figure of a crucified Christ

Now You See It—Now I Don’t

Interestingly, not everyone experiences pareidolia in the same way—or at all—and it seems that it is influenced by culture. Psychologists note that seeing meaning in random data is more likely among people with strong beliefs in religion or the paranormal. That accounts for the large number of instances of pareidolia involving religious symbols or figures ranging from the aforementioned Shroud, to sightings of the Hindu monkey god in a Singapore tree, and 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 in the Moon that every Western child knows is the Moon Rabbit in Asia. It is known as the Moon Buffalo, Dragon, or Frog in various other cultures. That’s also the reason you may argue with a friend about what shape you see in the fluffy cloud scudding overhead.

Auditory Pareidolia

Pareidolia isn’t limited to seeing. 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.”

Pareidolia In Art and Science

It may seem that pareidolia leads only to silly and sometimes creepy outcomes. But psychologists exploit it 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’Keefe’s flower paintings, for example, outrage some viewers—and delight others—who see suggestions of female genitalia in them.

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 to rock formations, just as the ancients did. Ultimately, this once again shows why you need to question absolutely everything.