Idioglossia refers to an idiosyncratic language, one invented and spoken by only one or a very few people. Most often, idioglossia refers to the “private languages” of young children, especially twins. It is also known as cryptophasia, and commonly referred to as twin talk or twin speech. Children who are exposed to multiple languages from birth are inclined to create idioglossias, but these languages usually disappear at a relatively early age.
Poto and Cabengo are a pair of identical twin girls (real names Grace and Virginia Kennedy, respectively), who used a secret language up to the age of about 8. Poto and Cabengo is also the name of a documentary film about the girls made by Jean-Pierre Gorin and released in 1979.
They were apparently of normal intelligence and developed their own communication because they had little exposure to spoken language in their early years. They were left in the care of a grandmother, who met their physical needs but did not play or interact with them. The grandmother spoke only German, while the parents spoke English. They had no contact with other children, seldom played outdoors, and were not sent to school.
Their father later stated in interviews that he realized the girls had invented a language of their own, but since their use of English remained extremely rudimentary, he had decided that they were in fact retarded and that it would do no good to send them to school. When he lost his job, he told a caseworker at the unemployment office about his family, and the caseworker advised him to put the girls in speech therapy. At Children’s Hospital of San Diego, speech therapist Alexa Kratze quickly discovered that Virginia and Grace, far from being retarded, had at least normal intelligence, and had invented a complex idioglossia.
Their language was spoken extremely quickly and had a staccato rhythm. These characteristics transferred themselves to the girls’ English, which they began to speak following speech therapy. Linguistic analysis of their language revealed that it was a mixture of English and German with some neologisms and several idiosyncratic grammatical features.
Many speech and hearing experts, as well as psychiatrists, offered speculation as to why the girls had not picked up English, as most idioglossic twins do as they go along whether or not they retain their personal language. Kratze pointed out that the girls had had very little contact with anyone outside their family, and that contact within the family had been minimal at best. These factors contributed to the girls’ developmental disability, even if they had been born with normal intelligence.
Once it was established that the girls could be educated, their father apparently forbade them to speak their personal language. He was quoted in Time magazine as saying “They don’t want to be associated as dummies. You live in a society, you got to speak the language.” Asked if they remembered their language, the girls confirmed that they did, but their father quickly stepped in to chide them for “lying”. They were mainstreamed and placed in separate classes in elementary school. However, they were still affected by their family’s emotional neglect.