Title: Why Some People See Ghosts and Other Apparitions | Psychology Today
Headings: Why Some People See Ghosts and Other Apparitions
Frank T. McAndrew Ph.D.
Why Some People See Ghosts and Other Apparitions
There are potential explanations (even if some people won't believe them).
The "Sensed Presence"
We Have "Agency-Detection" Mechanisms
When Do Sensed Presences Occur?
Religion Can Play a Role in Seeing Ghosts
Rites of Passage

Content: Psychologists refer to it as the “ sensed presence, ” and it is one of many reasons that most scientists remain very skeptical about the existence of ghosts. The "Sensed Presence"
The sensed presence usually happens to individuals who have become isolated in an extreme or unusual environment, often when high levels of stress are involved. These individuals report a perception or feeling that another person is there to help them cope with a hazardous situation. The vividness of the presence can range from a vague feeling of being watched to a clearly perceived, seemingly flesh-and-blood entity such as Clooney’s character in Gravity . This entity might be a god, a spirit, an ancestor, or someone personally known to the observer. Sensed presences usually appear in environments with little variation in physical and social stimulation; low temperature is also a common ingredient. Possible explanations for a sensed presence include the motion of boats, atmospheric or geomagnetic activity, and altered sensations and states of consciousness induced by changes in brain chemistry triggered by stress, hypothermia, a lack of oxygen, monotonous stimulation, or a buildup of hormones. There is in fact exciting new evidence from a research group led by Olaf Blanke demonstrating that it is the precise stimulation of specific brain regions that tricks people into feeling the "presence" of a ghostly apparition. Environmental psychologist Peter Suedfeld also thinks that what we do cognitively changes under these circumstances and may play a role.