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.
[1] Although not designed to study language, similar experiments on primates (labelled the "pit of despair") utilising complete social deprivation resulted in serious psychological disturbances.
[3][4] 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.
The experiments were recorded by the monk Salimbene di Adam in his Chronicles, who was generally extremely negative about Fredrick II (portraying his calamities as parallel to the Biblical plagues in The Twelve Calamities of Emperor Frederick 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 (which he took to have been the first), or Greek, or Latin, or Arabic, or perchance the tongue of their parents of whom they had been born.
"[5][full citation needed] A few 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.