Alien abduction, sometimes also called abduction phenomenon, alien abduction syndrome or UFO abduction, is a personally held belief in which the alleged "abductee" describes "subjectively real experiences" of being secretly kidnapped by non-human entities (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". In 2019, the U.S. navy admitted the existence of "Unidentified Aerial Phenomena", but did not ascribe them to aliens or another cause.
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. UFO, alien abduction and mind control plots can also be part of radical political apocalyptic and millenarian narratives.
Reports of the abduction phenomenon have been made all 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.
UFO abduction cases have been in decline over the years, with the last notable claim made in 1994.