Language deprivation experiments

Language deprivation experiments have been attempted several times through history, isolating infants from the normal use of language in an attempt to discover the fundamental character of human nature or the origins of language.

The American literary scholar Roger Shattuck called this kind of research study "The Forbidden Experiment" due to the exceptional deprivation of ordinary human contact it requires. Although not designed to study language, similar experiments on primates utilising complete social deprivation resulted in psychosis.

In history
Ancient records suggest that this kind of experiment was carried out from time to time, though the authenticity of these records can neither be confirmed nor denied. An early record of an experiment of this kind can be found in Herodotus's History. According to Herodotus, after carrying out such an experiment, the Egyptian pharaoh Psammetichos concluded the Phrygian race must predate the Egyptians since the children had first spoken the Phrygian word bekos, meaning "bread."

An alleged experiment 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 unto Adam and Eve by God.

The experiments were recorded by the monk Salimbene di Adam in his Chronicles, who wrote that Frederick bade "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 (which had been the first), 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 experiment, James V of Scotland sent two children to be raised by a mute woman in a specially-constructed cabin, to determine if language was learned or innate. Since neither child ever spoke, he determined that language must be learned. This experiment was later repeated by the Mughal emperor Akbar, who held that speech arose from hearing, thus children raised without hearing human speech would become dumb.

In fiction

 * This experiment occurs in Paul Auster's The New York Trilogy
 * In the Twilight Zone episode "Mute" (1963), several children are raised in such a manner to foster telepathic communication.
 * In Batgirl comics, the title character Cassandra Cain, in order to become a human weapon, is raised from childhood learning martial arts and body language instead of any spoken language.