What is a psychic? A psychic is some who is thought to possess the powers of knowing - or being able to learn - information that is not available through the use the five human senses (i.e. touching, tasting, smelling, feeling, hearing). This "sixth sense" is sometimes called "extrasensory perception" or "ESP". It is sometimes categorized as an occult practice.
Why would someone go to a psychic? People go to psychics, and sometimes pay a lot of money for a consultation, because they are attempting to acquire knowledge about something (e.g. the future) than they don't presently have. Customers believe the psychic can uncover information that will be useful to them.
What percentage of the population believes in psychics today? A Gallup Poll was conducted in 2005, which found that 41% of respondents believed in extrasensory perception (or ESP). 41% believed in clairvoyance and 31% believed in telepathy or psychic communication. 
Psychics: def inti on, history, and modern practices
Etymology, or word history
What does the word "psychic" mean?
The word has a Greek origin and has two primary meanings: (1) it can refer to the "mind," and either describe intellectual or psychological traits, and (2) it can refer to the "soul," which may refer to personal aspects such as the will. Other times when the word was used in ancient Greece, it meant "life," as in the entirety of a person's being. Today, the word can be found in the suffix of terms like "psychology" and "psychosis."
The belief in extrasensory ability is found in the oldest known civilizations and cultures, though it has many forms. Several cultures, no matter where they are located in the world, have contained different forms of occult behavior (i.e. seeking to uncover information that is presently hidden). Forms of psychic phenomena that can be found in other religious practices in the ancient world are sorcery, shamanism, and witchcraft.
What is the modern history of psychics?
Psychic practices became well-known in Europe and the United States in the 1800's. The primary form of this was necromancy in the form of mediumship. A "medium" is someone who is believed to have a special gift or ability that enables them to communicate with deceased people. Incredible stories were told, verbally and in print, about people like Daniel Dunglas Home, Helena Blavatshy, and Edgar Cayce.
In the 20th century, psychics became heavily associated with the New Age movement.
Skeptics believe that psychic abilities are a figment of the imagination. Some doubters believe that the psychic knows their "gifts" are fraudulent, but think the psychic shares the same beliefs that their customers do. Critics also point to studies done by reputable groups, such as the U.S. National Academy of Sciences, which have concluded that psychic abilities don't hold up to scrutiny. Where can psychics be found and who are some well-known psychics today? Psychics are found all over the world and in all types of cultures. In recent years, psychics have established a heavy television and internet presence. Well-known psychics, mostly made famous through television shows and commercials, include "Miss Cleo," John Edward, and Sylvia Browne. Edgar Cayce and Uri Gellar are famous psychics from a generation ago.
1. Druckman, D. and Swets, J. A. eds. (1988). Enhancing Human Performance: Issues, Theories and Techniques. National Academy Press, Washington, D.C. p. 22. 2. ibid. 3. Wikipedia, "psychic"