Skeptical analysis

While some accept ghosts as a reality, many others are skeptical of ghosts' actuality.

Skeptics may seek to explain ghost sightings by applying the principle of Occam's razor, which argues that the simplest adequate explanation for any event or phenomenon is the most likely explanation.

This usually means that first the sincerity and motive of the person reporting will be called into question. For example, lingering of ghosts is typically associated with seeking justice or revenge. Ascribing such motives and powers to dead people could be interpreted as a scare tactic directed at those who might consider murdering someone.

Second, the possibility of a hoax or con will be considered, with the reporting person assumed to be the victim. It seems possible that, sometimes, the telling of ghost stories might have been a way for secluded communities to scare off intruders. It is also conceivable that, when unsuccessful, this tactic could have been enhanced by more or less elaborate setups with members of that community playing ghosts.

Third, explanations grounded in knowledge about human physiology will be proffered. For instance, the appearance of ghosts is often associated with a chilling sensation and pale, semitransparent figures. But a natural animal response to fear is hair raising, which could be mistaken for chill.

The visual aspects of ghost reports could also be accounted for by human physiology: the peripheral vision is very sensitive in detecting motion, but does not contain much color or provide focused shapes; therefore, a moving curtain or other movement outside the focused view can create a strong illusion of an eerie figure.

The natural occurrence of infrasound, which are sounds below human auditory frequencies (below 20 hertz), could possibly explain the notions of feeling a "presence" in the room, or unexplained feelings of anxiety or dread, as certain infrasonic frequencies are known to have these effects on the body.

Psychological factors are also often cited as natural explanations for ghost sightings: susceptible people might be prone to exaggerated interpretations of perceptions when visiting a site of unpleasant historical events. Certain images such as paintings and movies might "program" a person to automatically associate a certain structure or area as haunted because of what he has seen in the movies.