Identical twins invent their own secret language only they understand

Picking up a second or third language has its challenges, but two twin brothers have put the nation's Duolingo streaks to shame by inventing their very own 'twin talk'.

Identical twins Matthew and Michael Youlden from Manchester invented 'Umeri' when they were toddlers and have used it ever since. Only they can understand it, and they are the only two people in the world who can speak it.

The twins, known as @Superpolygotbros on Instagram, created the language before having the ability to write.

The phenomenon is a unique form of communication known as cryptophasia, a language developed by twins that only they can understand. The word derives from the Greek 'crypto', meaning secret, and 'phasia', meaning speech.

An estimated 30-50 per cent of twins experience cryptophasia.

"Umeri isn’t ever reduced to a language used to keep things private," the identical twin brothers told the BBC. "It definitely has a very sentimental value to us, as it reflects the deep bond we share as identical twins."

"Twins have this shared language, that at some point they stop using, as if they feel ashamed of it," Matthew added. When their family and friends first picked up on their interactions, they shrugged: "'They’re off doing the language thing again.'"

To make matters more interesting, Matthew and Michael can already speak 25 languages each. These include French, Italian, Spanish, Mandarin, Dutch and Basque – a language used in the Basque Country.

Nancy Segal, director of the Twin Studies Center at California State University, delved into the phenomenon in her book Twin Mythconceptions where she referred to cryptophasia as "private speech" and "shared verbal understanding".

"Based on available studies, it is safe to say that about 40 per cent of twin toddlers engage in some form of 'twin-speak'," she wrote. "But that figure does not convey just how complex twins' language development turns out to be."

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