Language deprivation experiments have been claimed to have been attempted at least four times through history, isolating infants from the normal use of spoken or signed language in an attempt to discover the fundamental character of human nature or the origin of language. The truth about these claims is highly doubtful, accounts being usually based on only one questionable source. The American literary scholar Roger Shattuck called this kind of research study "The Forbidden Experiment" because of the exceptional deprivation of ordinary human contact it requires. Although not designed to study language, similar experiments on non-human primates utilising complete social deprivation resulted in serious psychological disturbances.
In history
Throughout history, several rulers have been blamed to have carried out this kind of experiment although most accounts seem to be myths: An early record of a study of this kind can be found in Herodotus's Histories. According to Herodotus, the EgyptianpharaohPsamtik I carried out such a study, and concluded the Phrygian race must antedate the Egyptians since the child had first spoken something similar to the Phrygian word bekos, meaning "bread". Recent researchers suggested this was likely a willful interpretation of their babbling. An experiment allegedly carried out by Holy Roman Emperor Frederick II in the 13th century saw young infants raised without human interaction in an attempt to determine if there was a natural language that they might demonstrate once their voices matured. It is claimed he was seeking to discover what language would have been imparted into Adam and Eve by God. The experiments were recorded by the monk Salimbene di Adam in his Chronicles, who was generally extremely negative about Fredrick II and wrote that Frederick encouraged "foster-mothers and nurses to suckle and bathe and wash the children, but in no ways to prattle or speak with them; for he would have learnt whether they would speak the Hebrew language, or Greek, or Latin, or Arabic, or perchance the tongue of their parents of whom they had been born. But he laboured in vain, for the children could not live without clappings of the hands, and gestures, and gladness of countenance, and blandishments." Several centuries after Frederick II's alleged experiment, James IV of Scotland was said to have sent two children to be raised by a mute woman isolated on the island of Inchkeith, to determine if language was learned or innate. The children were reported to have spoken good Hebrew, but historians were skeptical of these claims soon after they were made. Mughal emperorAkbar was later said to have children raised by mute wetnurses. Akbar held that speech arose from hearing; thus children raised without hearing human speech would become mute. Critical authors have shed doubt on the veracity of the accounts: Probably neither Psamtik I nor James IV ever conducted any such studies, and probably neither did Frederik II. Only Akbar's study is most likely authentic, but offers an ambiguous outcome.
In fiction
The "forbidden experiment" occurs in Paul Auster's The New York Trilogy.
In The Twilight Zone episode "Mute", several children are raised in such a manner to foster telepathic communication.
In Le Miroir de Cassandre by Bernard Werber, the title character Cassandre and her older brother are deprived of spoken language during a part of their childhood as an experiment from their mother, a famous paedopsychologist