Twins are regularly reported to invent languages of their own, unintelligible to others. These languages are known as autonomous languages, cryptophasia or idioglossia. Despite current belief, this is not a rare phenomenon. Autonomous languages exist in about 40% of all twins, but often disappear soon.
The theory behind this "twin language" goes a little something like this: twins are so close to each other and rely on each other so much that they don't have as much of a need to communicate with the outside world, so they make up their own idiosyncratic language that develops only between the two of them.
About 40% of twins, generally monozygotic or identical twins, will develop some form of autonomous language, using nicknames, gestures, abbreviations, or terminology that they only use with each other. While parents and siblings can often discern the meaning, the twins generally don't use the terms with others.
Numerous studies have established that twins, triplets and other sets of multiples have a higher likelihood of speech delays. (It's also more common in identical twins and multiples than in fraternal.)
Identical twins share a particularly intense bond. They are the result of one fertilized egg splitting into two, giving them identical DNA. (Fraternal twins are the result of two separate, genetically different fertilized eggs.) As a result, identical twins are as close as two people can be.
Monoamniotic-monochorionic Twins
This is the rarest type of twin, and it means a riskier pregnancy as the babies can get tangled in their own umbilical cords.
The hardest thing about having twins is…
“Managing the movement of two babies. Carrying them both up and down the stairs, getting them into the car, etc.” —Simeon R. “Often having to make one baby wait!” —Catharine D. “Being outnumbered—the logistics of two on one is definitely the hardest.
Poto and Cabengo (names given, respectively, by Grace and Virginia Kennedy to themselves) are American identical twins who used an invented language until the age of about eight. Poto and Cabengo is also the name of a documentary film about the girls made by Jean-Pierre Gorin and released in 1980.
Similar to the mind-reading myth, there are things that can't be explained. There are twins who say they have felt each other's pain. And their close relationship and nearly-identical physical structure means there could be a sliver of truth in the theory — as pain can be psychological and can be felt empathetically.
Twins Become Aware of Each Other in the Utero
According to multiple studies that include 3D ultrasounds, twins start to reach out and touch each other in the womb starting at about 14 weeks. At about 18 weeks, they touch each other more often.
In Madagascar, the Antambahoaka tribe considers twins a curse, an abomination. According to tradition, if a woman gives birth to twins, she is expected to abandon them or face becoming ostracised by the community.
Fortunately telling twins apart is one fear that can be taken off the list. Most parents find that mixing up their babies is the least of their concerns. After only a few hours or days at most, they are distinguishable as individuals. Even if they look alike, parents just know the difference.
Autonomous languages exist in about 40% of all twins, but often disappear soon. In this study, nine autonomous languages are compared: the circumstances in which they emerge, how these languages relate to the parents' language (the model language) and how they are structured.
Being a twin has its benefits—tricking people, having a lifelong companion, sharing clothes—but it also has downsides. Many twins struggle to cultivate their own identities, while being so similar to one another. And that struggle lasts a lifetime, according to a recent study.
It is likely that twins' awareness of one another starts sooner than seven or eight months of age. An article by the late doctor, T. Berry Brazelton, observed that at age three to four months, an infant identical female twin seemed disoriented when her sister was removed from the room.
Cryptophasia is when twins, identical or fraternal, use a speech that only the two siblings can understand (twin speak). Over 50% of young twins form their own type of this communication.
It was concluded, among many other things, that identical twins are about 85 percent similar for IQ, whereas fraternal twins are about 60 percent similar. This would seem to indicate that half of the variation in intelligence is due to genes.
While June and Jennifer had the ability to speak, and in fact did speak to Wallace and a few others, they made a pact not to communicate with most people, including their family, at age 3. The longer they went without speaking, the more they felt they had to stay silent.
But the jury's out on whether or not twins have a full language, known only to them. There's a term — idioglossia — for a form of communication only twins can understand. But it's actually fairly rare for them to develop their own complete language — in most cases it's just repetitive babble.
Multiples are about twice as likely as singleton babies to have birth defects, including neural tube defects (such as spina bifida), cerebral palsy, congenital heart defects and birth defects that affect the digestive system. Growth problems. Multiples are usually smaller than singleton babies.
Just like singleton babies, twins can sometimes get super-active in the womb. But not to worry — there's no real threat from it! Babies can kick or even hit each other (yes, really) in utero, but the good news is the amniotic fluid acts as a cushion to protect them from actually getting hurt by any of it.
And because the death rate in the womb is higher for twins than for singleton births, female twins are more common than male twins.
This is why fraternal twins run in families. However, only women ovulate. So, the mother's genes control this and the fathers don't. This is why having a background of twins in the family matters only if it is on the mother's side.
Once the babies are large enough to stay in one position in the womb, the twin lowest in the uterus is known as Baby A and the one furthest from there is Baby B, according to the Stanford Medicine News Center. In the majority of vaginal births, Baby A is born first.