Double Talk: Do Your Twins Speak a Secret Language?


A few months ago when Kari Butler’s twin boys (she’s thinks they’re fraternal but has not had them tested), Spencer and Parker, were 21 months old, she noticed them engaged in a conversation that was completely foreign to her. “I was in the kitchen with Parker and Spencer was in the playroom. Spencer babbled something loudly to Parker and then Parker babbled back,” explains the New Lebanon, Ohio mom. With Butler close on his heels, Parker then walked into the playroom to join his cotwin as if responding to a request. The two boys continued their private exchange while playing on their rocking horses as Butler watched in awe. “I was amazed,” she says. “I have heard of ‘twin talk’ but this was the first time I’d really seen it.”

Young twin girl whispers in her sister's ear.

For decades, the idea that some twins develop their own language has been a source of great fascination for both parents and researchers. But can some twins really invent a unique language that no one else can understand?

Probably not, researchers say.

The Difference Between Private Language and Shared Understanding

“The confusion comes because in twin children we observe two phenomena that are defined by parents as the single phenomenon known as twin language, secret language, or autonomous language,” explains Karen Thorpe, Ph.D., Professor, School of Psychology at Queensland School of Technology in Australia, and the co-author of several research studies on this intriguing topic. To clear up the confusion, Thorpe calls the first type of twin language ‘private language,’ a rare form of communication used exclusively between the pair and not with anyone else. It usually occurs in twins that live in somewhat isolated conditions, perhaps in homes with little social interaction or verbal stimulation. Researchers also suggest that poor cognitive functioning can play a part in twins who use private language.

The second and much more common type of twin language is ‘shared understanding,’ a normal development phase where twins are able to interpret each other’s immature, unclear, or imperfect speech. In other words, as your tiny talkers learn the rules of speech, babbling away and practicing what they hear around them every day, they tend to understand what the other is saying before you do! Hence, it gives the appearance of a “secret twin language.” (Although most common in twins, Thorpe explains that it can crop up with close siblings and friends, too.) ‘Shared understanding’ can also include made-up words or phrases and verbal shorthand. It usually crops up when twins are toddlers and then slowly fades with time as they master correct English usage. Thorpe calls ‘shared understanding’ a normal social phenomenon and not some amazing or pathological feature of speech or language.


Why Does “Twin Talk” Happen?

Some reports suggest that nearly 40 percent of twins engage in some form of this “twin talk.” But why such a high number? One explanation is the close relationship that many multiples share. Twins are naturally “high access” siblings, spending much more time with each other than say, two singleton siblings born years apart. Thorpe says that twins are at an advantage since they have much more knowledge of each other and the circumstances surrounding their relationship. “The children are able to understand each other’s immature or imperfect speech because they know each other, share a social world and history,” Thorpe says. “It’s not anything out of the ordinary or different in twins. It’s much like married adults who are better able to understand each other because they are close.”

It’s during their continued togetherness that many young twins also learn to model their cotwins’ burgeoning language, reinforcing their mistakes. In addition, researchers speculate that identical twins or twins who are very similar developmentally are more prone to using some form of twin language.

Lori Reyes of Hilltown, Penn. says her six-year-old identical twin sons, Nico and Cruz, have been using a form of twin language on and off since they were young toddlers. “They never speak to anyone else in ‘twin,’ only to each other. I watch from the sidelines,” she explains. Although her sons used their special lingo more when they were younger, Reyes says it still pops up periodically during playtime or in times of stress like the first day of school or at a doctor’s appointment. “We’re a bilingual family but they communicate together in English with a few ‘twin’ words thrown in as if they are nouns or verbs. They do this without skipping a beat in their speech pattern.”

Can a Twin Language Lead to Speech Delay?

Although ‘shared understanding’ with typical patterns of immature speech shouldn’t be a cause of concern, Thorpe cautions parents to pay attention and monitor their children’s language development closely. “Though twin children are on average slower to develop language, being a twin should not mean that language delay is inevitable,” she adds. “Failing to meet milestones of using words and sentences or not being understood by people who know the children are all important indicators of a need to seek professional advice.” It’s important to intervene early, too, as language delay may lead to problems later on in school such as learning to read, write, and spell.

Judith Andersen’s three-year-old fraternal twin daughters, Lauren and Jenna, have been in speech therapy for six months to help break the code of their jargon and get their English up to speed. “I felt very left out by their language and it was extremely frustrating trying to figure out what they wanted,” says the Livingston, New Jersey mom. “They were evaluated at two years and two months because they were not speaking English. They were speaking “twinnish.” Her daughters were not using two-word sentences and had a vocabulary of only 20 words when 50 was the norm for their age. Today, with the help of therapy, the girls are using three- to four-word sentences and their vocabulary has shot up to more than 50 words. “We’re just working on articulation now. Their twin language is gone except for a few remaining words.”

Jenn Duke of High Point, North Carolina says her three-year-old identical twin boys, Cameron and Caden, speak a mixture of English and “twin.” “It’s as if they are speaking completely clear and normal to each other but we don’t always know what they are saying,” she says. Their use of ‘shared understanding’ isn’t a cause of concern, however, since the boys can “turn it off” and communicate to mom and dad easily. “I don’t mind when they do it because it’s cute and their speech is fine.”

And there lies the distinction according to Thorpe. “Some children have a communication together but also are competent speakers to others,” she says. “If children are playing with language together, understand each other well, and talk to people other than their cotwin in a way consistent with developmental norms, there would not appear to be a problem.”

Yet even if your young twins are struggling to be understood, Thorpe remains optimistic. Her research suggests that language delay in most twins is associated with a lack of social experiences. You can improve your twins’ speech, she says, by simply increasing and expanding their interactions with adults as well as other children.

Double play date, anyone?

A copy of the book Double Duty.