The terms alien abduction or abduction phenomenon describe "subjectively real experiences" of being secretly kidnapped by nonhuman figures (aliens) and subjected to physical and psychological experimentation. Most scientists and mental health professionals explain these experiences by factors such as suggestibility (e.g. false memory syndrome), sleep paralysis, deception, and psychopathology. Skeptic Robert Sheaffer sees similarity between the aliens depicted in science fiction films, in particular Invaders From Mars (1953), and some of those reported to have actually abducted people. People claiming to have been abducted are usually called "abductees" or "experiencers".
Typical claims involve forced medical examinations that emphasize the subject's reproductive systems. Abductees sometimes claim to have been warned against environmental abuse and the dangers of nuclear weapons. The contents of the abduction narrative often seem to vary with the home culture of the alleged abductee.
Reports of the abduction phenomenon have been made around the world, but are most common in English speaking countries, especially the United States. The first alleged alien abduction claim to be widely publicized was the Betty and Barney Hill abduction in 1961.
There are many hundreds of documented claims of abductions, namely instances when the witness of a close encounter has recalled under hypnosis about being forcibly taken inside a UFO. The witnesses generally describe being subject to medical examination (often causing trauma and pain). These claims are substantiated by scars on the body and missing time in their conscious recollections during that period.
The encounters remembered by witnesses, if they occurred at all, should be treated at the symbolic level. They do not provide information about the extraterrestrial origin of the beings. To the extent that there is underlying reality to the UFO phenomenon, they provide a physical support for human ability to use them as symbols in response to inner needs.