Pareidolia (pron.: // parr-i-DOH-lee-ə) is a psychological phenomenon involving a vague and random stimulus (often an image or sound) being perceived as significant, a form of apophenia. Common examples include seeing images of animals or faces in clouds, the man in the moon or the Moon rabbit, and hearing hidden messages on records when played in reverse.
The word comes from the Greek words para (παρά, "beside, alongside, instead") in this context meaning something faulty, wrong, instead of; and the noun eidōlon (εἴδωλον "image, form, shape") the diminutive of eidos. Pareidolia is a type of apophenia, seeing patterns in random data.
There have been many instances of perceptions of religious imagery and themes, especially the faces of religious figures, in ordinary phenomena. Many involve images of Jesus, the Virgin Mary, the word Allah, or other religious phenomena: In September 2007 in Singapore, for example, a callus on a tree resembled a monkey, leading believers to pay homage to the "Monkey god" (either Sun Wukong or Hanuman) in the so-called "monkey tree phenomenon".
Publicity surrounding sightings of religious figures and other surprising images in ordinary objects has spawned a market for such items on online auctions like eBay. One famous instance was a grilled cheese sandwich with the Virgin Mary's face.
Various European ancient divination practices involve the interpretation of shadows cast by objects. For example, in molybdomancy, a random shape produced by pouring molten tin into cold water is interpreted by the shadow it casts in candlelight.
From the late 1970s through the early 1980s, Japanese researcher Chonosuke Okamura self-published a famous series of reports titled "Original Report of the Okamura Fossil Laboratory" in which he described tiny inclusions in polished limestone from the Silurian period (425 mya) as being preserved fossil remains of tiny humans, gorillas, dogs, dragons, dinosaurs, and other organisms, all of them only millimeters long, leading him to claim "There have been no changes in the bodies of mankind since the Silurian period ... except for a growth in stature from 3.5 mm to 1,700 mm." Okamura's research earned him a winner of the Ig Nobel Prize (a parody of the Nobel Prizes) in biodiversity. See List of Ig Nobel Prize winners (1996).
Projective tests 
The Rorschach inkblot test uses pareidolia in an attempt to gain insight into a person's mental state. The Rorschach is a projective test, as it intentionally elicits the thoughts or feelings of respondents which are "projected" onto the ambiguous inkblot images. Projection in this instance is a form of "directed pareidolia" because the cards have been deliberately designed not to resemble anything in particular.
Electronic voice phenomenon 
In his notebooks, Leonardo da Vinci wrote of pareidolia as a device for painters, writing "if you look at any walls spotted with various stains or with a mixture of different kinds of stones, if you are about to invent some scene you will be able to see in it a resemblance to various different landscapes adorned with mountains, rivers, rocks, trees, plains, wide valleys, and various groups of hills. You will also be able to see divers combats and figures in quick movement, and strange expressions of faces, and outlandish costumes, and an infinite number of things which you can then reduce into separate and well conceived forms."
Evolutionary advantage 
Carl Sagan hypothesized that as a survival technique, human beings are "hard-wired" from birth to identify the human face. This allows people to use only minimal details to recognize faces from a distance and in poor visibility but can also lead them to interpret random images or patterns of light and shade as being faces. The evolutionary advantages of being able to discern friend from foe with split-second accuracy are numerous; prehistoric (and even modern) men and women who accidentally identify an enemy as a friend could face deadly consequences for this mistake. This is only one among many evolutionary pressures responsible for the development of the facial recognition capability of modern humans.
In Cosmos: A Personal Voyage Sagan claimed that Heikegani crabs' occasional resemblance to Samurai resulted in their being spared from capture and thus exaggerate the trait in their offspring, a hypothesis proposed by Julian Huxley in 1952. Such claims have been met with skepticism.
A 2009 magnetoencephalography study found that objects incidentally perceived as faces evoke an early (165 ms) activation in the ventral fusiform cortex, at a time and location similar to that evoked by faces, whereas other common objects do not evoke such activation. This activation is similar to a slightly earlier peak at 130 ms seen for images of real faces. The authors suggest that face perception evoked by face-like objects is a relatively early process, and not a late cognitive reinterpretation phenomenon. An fMRI study in 2011 similarly showed that repeated presentation of novel visual shapes that were interpreted as meaningful led to decreased fMRI responses for real objects. These result indicate that interpretation of ambiguous stimuli depends on similar processes as those elicited for known objects.
These studies help to explain why people identify a few circles and a line as a "face" so quickly and without hesitation. Cognitive processes are activated by the "face-like" object, which alert the observer to both the emotional state and identity of the subject – even before the conscious mind begins to process – or even receive – the information. The "stick figure face," despite its simplicity, conveys mood information (in this case, disappointment or mild unhappiness). It would be just as simple to draw a stick figure face that would be perceived (by most people) as hostile and aggressive. This robust and subtle capability is the result of eons of natural selection favoring people most able to quickly identify the mental state, for example, of threatening people, thus providing the individual an opportunity to flee or attack preemptively. In other words, processing this information subcortically (and therefore subconsciously) – before it is passed on to the rest of the brain for detailed processing – accelerates judgment and decision making when alacrity is paramount. This ability, though highly specialized for the processing and recognition of human emotions, also functions to determine the demeanor of wildlife.
Combined with Apophenia (identifying meaningful patterns in meaningless randomness) and hierophany (a manifestation of the sacred), pareidolia may have helped early societies organize chaos and make the world intelligible.
There are a number of conditions that can cause an individual to lose his/her ability to recognize faces; stroke, tumors, and trauma to the ventral fusiform gyrus are the most common culprits. This is known as prosopagnosia. Pareidolia can also be related to obsessive–compulsive disorder as seen in one woman's case.
Smiley face in Galle Crater on Mars
Human face on Pedra da Gavea near Rio de Janeiro, Brazil
Garuda (Ancient Eagle) seen from the sides of Tirumala Hills, India
Anthropomorphic grimacing face visible in the red shale of the gorges of Cians, France
Bust of a woman with a hat, in profile, in the gorges of Daluis, France, better known as "La Gardienne des Gorges"
Romanian Sphinx in Bucegi Mountains
See also 
- Zusne, Leonard; Warren H. Jones (1989). Anomalistic Psychology: A Study of Magical Thinking. Lawrence Erlbaum Associates. pp. 77–79. ISBN 0-8058-0508-7. Retrieved 2007-04-06.
- NY Times: "In New Jersey, a Knot in a Tree Trunk Draws the Faithful and the Skeptical" July 23, 2012
- Ibrahim, Yahaya (2011-01-02). "In Maiduguri, a tree with engraved name of God turns spot to a Mecca of sorts". Sunday Trust (Media Trust Limited, Abuja). Retrieved 2012-03-21.
- Ng Hui Hui (13 September 2007). "Monkey See, Monkey Do?". The New Paper. pp. 12–13.[dead link]
- "'Virgin Mary' toast fetches $28,000". BBC News. 23 November 2004. Retrieved 2006-10-27.
- Spamer, E. "Chonosuke Okamura, Visionary". Philadelphia: Academy of Natural Sciences. archived at Improbable Research
- Berenbaum, May (2009). The earwig's tail: a modern bestiary of multi-legged legends. Harvard University Press. pp. 72–73. ISBN 0-674-03540-2.
- Marc Abrahams (2004-03-16). "Tiny tall tales: Marc Abrahams uncovers the minute, but astonishing, evidence of our fossilised past". London: The Guardian.
- Conner, Susan; Kitchen, Linda (2002). Science's most wanted: the top 10 book of outrageous innovators, deadly disasters, and shocking discoveries. Most Wanted Series. Brassey's. p. 93. ISBN 1-57488-481-6.
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- John R; J. Don Read (1923). "Leonardo Da Vinci S Note-Books Arranged And Rendered Into English". Empire State Book Company..
- Sagan, Carl (1995). The Demon-Haunted World – Science as a Candle in the Dark. New York: Random House. ISBN 0-394-53512-X.
- Svoboda, Elizabeth (2007-02-13). "Facial Recognition – Brain – Faces, Faces Everywhere". The New York Times (New York Times). Retrieved July 3, 2010.
- Joel W. Martin (1993). "The Samurai Crab" (PDF). Terra 31 (4): 30–34.
- Hadjikhani N, Kveraga K, Naik P, Ahlfors SP (February 2009). "Early (M170) activation of face-specific cortex by face-like objects". Neuroreport 20 (4): 403–7. doi:10.1097/WNR.0b013e328325a8e1. PMC 2713437. PMID 19218867.
- Voss first1=JL last2=Federmeier first2=KD last3=Paller first3=K (2011). "The potato chip really does look like Elvis! Neural hallmarks of conceptual processing associated with finding novel shapes subjectively meaningful". Cerebral Cortex. doi:10.1093/cercor/bhr315. PMID 22079921.
- "Dog Tips – Emotions in Canines and Humans". Partnership for Animal Welfare. Retrieved July 3, 2010.
- Bustamante Patricio, Yao Fay, Bustamante Daniela, 2010 b, The Worship to the Mountains: A Study of the Creation Myths of the Chinese Culture
- Bustamante, Patricio; Yao, Fay; Bustamante, Daniela (2010). "Pleistocene Art: the archeological material and its anthropological meanings" (PDF). Text "From Pleistocene Art to the Worship of the Mountains in China. Methodological tools for Mimesis in Paleoart, Congress IFRAO 2010 – 'Pleistocene Art of the World'. Symposium. Signs, Symbols, Myth, Ideology " ignored (help)
- Fontenelle, Leonardo. "Leonardo F. Fontenelle. Pareidolias in obsessive-compulsive disorder". Retrieved October 28, 2011.
|Wikimedia Commons has media related to: Pareidolias|
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- Skepdic.com Skeptic's Dictionary definition of pareidolia
- Lenin in my shower curtain (Bad Astronomy)
- The Stone Face: Fragments of An Earlier World
- Feb. 13, 2007, article in The New York Times about cognitive science of face recognition
- Famous Pareidolias
- Snopes.com Faces of 'Satan' seen in World Trade Center smoke