Extra-sensory perception, or ESP, is the ability to acquire information by means other than the known senses of taste, sight, touch, smell, hearing, balance and proprioception. The term implies sources of information as yet unknown to science.

Specific types of extra-sensory perception include: Perception of events in other places (clairvoyance, clairaudience, clairgustance, clairsentience) and in other times (precognition, retrocognition, second sight) Perception of aspects of others not perceivable by most people (aura reading)

The ability to sense communications from, and communicate with, people far away (telepathy), beyond the grave (mediumship, séancing, and spirit walking), or in other dimensions (astral projection)

The study of these abilities, called parapsychology, includes other phenomena such as psychometry and psychokinesis, which are associated with ESP. A person capable of using ESP is referred to as a psychic or as having psychic powers

The term has been attributed to Sir Richard Burton in the 1870s, although Gustav Pagenstecher (Pagenstecher, 1924) made a more concrete use of the term. Other authors, such as Dr. Rudolph Tischner in the 1920s, also used this concept to describe a form of “externalization of sensibility.” ESP phenomena are traditionally classified into three categories.

These are:

(1) telepathy, understood as the awareness of the thoughts or feelings of another person;

(2) clairvoyance, or awareness of objects, events, or people without the use of the known senses; and

(3) precognition, or the knowledge of future events.

The first studies of ESP were conducted in the 1880s. This early work consisted mostly of investigations of cases and “gifted” individuals. The study of ESP progressed, becoming more and more scientific in the first quarter of the century. It was in the 1930s when J. B. Rhine conducted a series of experiments at Duke University which called the attention of the scientific community to the research.

Some theorists argue that ESP is the remnant of an ancient sense which has deteriorated in human beings as their cultures have developed. Conversely, other theorists claim that ESP is a “supersense” which evolved in the nervous system. There are also speculations that some people (psychics) are born with this gift. However, research supports that everyone is born with ESP capability, although some may possess more than others. This is reinforced by the fact that, according to survey work, most people report having experienced ESP at least once in their lives.

One of the first theories on the nature and functioning of ESP was put forward by Frederic W. H. Myers in his Human Personality and Its Survival of Bodily Death published in 1903. This author described ESP in terms of a particular functioning of perception that occurred below the threshold of consciousness. Myers realized that a large number of the reported cases of ESP occurred while percipient were experiencing an altered state of consciousness. He suggested that this phenomenon could be most noticeable in dreams, trance states, or hypnosis. Laboratory studies on dream ESP, such as the Maimonides dream telepathy study, as well as hypnosis studies.