Body swaps, first popularized in Western Anglophone culture by the personal identity chapter of John Locke's Essay Concerning Human Understanding, have been a common storytelling device in fiction media. Novels such as Vice Versa (1882) and Freaky Friday (1972) have inspired numerous film adaptations and retellings, as well as television series and episodes, many with titles derived from "Freaky Friday". In 2013, Disney Channel held a Freaky Freakend with seven shows that featured body-swapping episodes. This list features exchanges between two beings, and thus excludes similar phenomena of body hopping, spirit possession, transmigration, and avatars, unless the target being's mind is conversely placed in the source's body. It also excludes age transformations that are sometimes reviewed or promoted as body swaps, as in the movies Big and 17 Again; identity/role swaps, typically between clones, look-alikes, or doppelgängers; and characters with multiple personalities.