Language deprivation experiments have been attempted several 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 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 non-human primates utilising complete social deprivation resulted in psychosis.
Ancient records suggest that this kind of experiment was carried out from time to time, though the authenticity of these records is unconfirmable. An early record of an experiment of this kind can be found in Herodotus’s Histories. According to Herodotus, after carrying out such an experiment, the Egyptian pharaoh Psamtik I concluded the Phrygian race must predate the Egyptians since the child had first spoken something similar to 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.