People sometimes misperceive objects they cannot see well, or are unfamiliar with, as other things from their visual memory. But why do ghostly figures feature so frequently in these visual substitutions? Why not letter boxes, buses or book cases?
Mind and body a default brain concept
The answer may lie in the way our brains work. We understand the difference between living and inanimate objects from an early age. We view living and non-living objects in quite different ways in our brain. This 'dual view' leads our brains to treat bodies and mind separately.
This appears to be a 'default' way of human thinking. It leads naturally to the common concept that mind and body are separable entities. It is just a small step from there to the idea of spirits. Despite the lack of compelling evidence, many people think that ghosts are spirits. This probably arises culturally. It is thus not too surprising that misperceptions often feature ghosts or other paranormal phenomena, rather than more mundane objects.
Seeing patterns that aren't there
We all have an ability to recognise patterns. It is probably a survival adaptation from the days when you needed to be able to see a 'tiger in the long grass' because your life depended on it. We are not always right about patterns, sometimes seeing them where there are none.
Research has shown that our pattern recognition ability goes into overdrive in stressful situations. This makes sense as, if you are worried that there IS a tiger in the long grass, you need your pattern recognition abilities more than usual. Human figures may feature frequently in misperceptions because they be seen as a threat (like a shadowy figure in a dark alley).
Some people feel stress in 'spooky' places. Indeed, you could define a spooky place as somewhere you feel discomfort because you think there may be ghosts present. Thus people may well recognise patterns that are not really there more often in spooky places. This could certainly contribute to misperception. So, in such situations, a tree in shadow might easily be misperceived as a human figure and interpreted as a ghost.
So the answer to 'why people misperceive ghosts' is probably a combination of the way our brain works, cultural influences (all those ghost stories) and overactive pattern recognition in spooky places. One might almost ask, why would people NOT see ghosts in such situations?
© Maurice Townsend 2009