Twin Speak: The Secret Language

Posted by Lindsay Geoffroy


If you are currently an internet user (which, if you are reading this, you probably are), then most likely you have seen the adorable viral video of the two infant twins babbling to each other. Although they are not forming any coherent words, they seem to understand each other perfectly and even crack each other up. Do these twin babies have their own secret twin language?


As it turns out, in the case of these two tots, what they are doing is actually just speaking gibberish. However, researchers have in recent decades have discovered a lingual phenomenon in twins, both identical and fraternal, called cryptophasia. Cryptophasia, which is Greek for “secret speech,” describes the occurrence when a set of twins, usually anywhere from 2-7 years of ages, invents their own language which only the two siblings can understand.

So how common is cryptophasia? As of 2010, twins accounted for about 3.3% of live births in the U.S., according to Of those twin births, it is estimated that about 50% of twin pairs will at some point go through a stage of cryptophasia.

Famous Cases/Why Does This Happen?

One of the most famous documented instances of cryptophasia is the case of Grace and Virginia Kennedy. Growing up in 1970’s Sand Diego, CA, the Kennedy sisters developed their own exclusive English-German hybrid language and referred to each other as “Poto” and “Cabengo.” Researchers picked up the case and found that the girls were of normal intelligence but had little interaction with parents, peers, or teachers who could help them to properly learn English. They also picked up German phrasing from their grandmother. As such, they only had each other with which to communicate, resulting in the formation of twin speak and a permanent stunt in formation of solid language skills. They had developed the speech out of necessity to speak with one another.

Another, less tragic example cryptophasia is the case of Irish Twins Matthew and Michael Youlden. The Youlden twins are now adults, but since childhood have been developing a cryptophasic language called Umeri. They do not share the details of the language and only speak it with each other; however, they have reported that the language has a dictionary, verb tenses, and is able to be typed. Although these twins are advanced in their linguistic skills, their twin speak also developed as a way to communicate exclusively with each other. They have continued developing Umeri so that their language can become as fully developed as possible.

While we here at Lionbridge probably can’t help interpret any cryptophasic languages, we can provide interpretation services in over 300 languages. To learn more, visit us here.