Parapsychology is the modern name for what used to be called psychical research. The word is usually used in a narrow sense, as scientifically based research, but sometimes it is used more broadly to cover the whole range of the occult. The term psi is often used as a briefer equivalent. Psi phenomena are paranormal, that is, beyond the range of what is considered to be part of the ordinary world.

The Society for Psychical Research (SPR) was established in England in 1882 and is given credit for organizing systematic research in the English-speaking Western world. Many of its founders were distinguished intellectuals who were themselves spiritualists and interested in immortality. The American Society for Psychical Research was founded soon after. Though some of the earlier researchers did scientific studies, they more often conducted other kinds of investigations of psi, investigating ostensible cases of dramatic psi, and frequently working...