Cryptophasia is a phenomenon of a language developed by twins (identical or fraternal) that only the two children could understand. The word has its roots from crypto meaning secret and phasia meaning speech. It has been reported that up to 50% of young twins will have their own twin language which they use to communicate only with each other and one that cannot be understood by others. "In all cases known, the language consists of imitation of the sound (for example 'meow' for a cat, 'Tic Tac' for clock, etc.), some coined term, word, or phrase, but for the greatest part of words from the adult language adapted to the constrained phonological possibilities of young children. These words being hardly recognizable, the language may turn out to be completely unintelligible to speakers of the parents' languages.
Twins and children from multiple births develop this ability, perhaps because of more interpersonal communication between themselves than with the parents, there is inadequate scientific proof to verify these claims. A delay in the phonological development of one or both twins is said to be a main cause of cryptophasia. Twins can develop the ability to communicate with one another without working within the grammar of their parents' language, thus possibly leading to a short-term delay in linguistic development of one or both twins.
June and Jennifer Gibbons, Barbadian-born Welsh twin sisters whose language was an example of cryptophasia and was exemplified by the twins' simultaneous actions, which often mirrored each other.
- An onomatopoeia is a word that phonetically imitates, resembles or suggests the source of the sound that it describes. (Eg: meow)
- A neologism is the name for a newly coined term, word, or phrase that may be in the process of entering common use, but that has not yet been accepted into mainstream language.