Experiential Source Hypothesis

The experiential source hypothesis is a hypothesis put forward by David Hufford in 1982, as a potential explanation for the similarities of unconnected events considered to be supernatural.

History and Explanation
Similarities between unconnected supernatural events across various cultures has been examined for quite some time. In 1894 Andrew Lang commented on the repetition of certain elements in stories of supernatural events from completely separate cultures, such as Australian Aborigines, ancient Egypt, and his contemporary London.

The cultural source hypothesis was another idea to explain the similarities of supernatural experiences, positing that it's cultural stories and tradition that shape people's ideas about the world, and thus the reason for similarities between various supernatural experiences. However this, while accounting for similarities within one culture, is less helpful in explaining them for unconnected ones. On the other hand the experiential source hypothesis suggests that some features of supernatural events are universal and unrelated to culture, and in fact are 'accurate observations interpreted rationally'

This suggests that while specific details of supernatural phenomena may be culturally derived (such as the specific name or purpose of an apparition), there are universal events that can happen to anyone that can inspire such stories.

A good example given by Hufford is the idea of sleep paralysis and Old Hag syndrome. A common feature of sleep paralysis is the sensation of feeling the presence of a supernatural entity of some kind. This has been experienced across nearly all cultures, but the exact details of the entity differ.