Parapsychology is the scientific and scholarly study of certain unusual events associated with human experience.

A long-held, common-sense assumption is that the worlds of the subjective and objective are completely distinct, with no overlap. Subjective is "here, in the head," and objective is "there, out in the world." Parapsychology is the study of phenomena suggesting that the strict subjective/objective dichotomy may instead be part of a spectrum, with some phenomena occasionally falling between purely subjective and purely objective. We call such phenomena "anomalous" because they are difficult to explain within current scientific models.

These anomalies fall into three general categories: ESP (terms are defined below), PK, and phenomena suggestive of survival after bodily death, including near-death experiences, apparitions, and reincarnation. Most parapsychologists today expect that further research will eventually explain these anomalies in scientific terms, although it is not clear whether they can be fully understood without significant (some might say revolutionary) expansions of the current state of scientific knowledge. Other researchers take the stance that existing scientific models of perception and memory are adequate to explain some or all parapsychological phenomena.