Its a twin thing
Are twins really two halves of the same person, or are
they just two individuals who happened to be born at the same time?
And can they really read each other's minds? Emma Fahy explores the
facts behind some fascinating twin theories.
There's something fascinating about twins, and despite the
increasing occurrence of twins associated with assisted
reproduction, they retain a sense of mystery and uniqueness that we
singletons can't help but envy. From the ill-fated Biblical pair
Jacob and Esau and the mythical founders of Rome, Romulus and
Remus, to modern-day heroes like the Evers-Swindell sisters,
history is peppered with famous twins, often shrouded in mystery
and intrigue. Perhaps it's because, unlike many animals, human
beings simply aren't designed to gestate more than one baby at a
time, so the very existence of twins is, in itself, a
miracle.
The fascination with twins goes back as
far as Hippocrates, the father of modern medicine, who first
conceived the concept of genetics while studying sets of twins.
Hippocrates identified a pair of brothers who shared many of the
same physical traits, and hypothesised that this was because they
had been born at the same time, and had therefore been subjected to
a similar experience prior to birth. Since then, twins as a group
have been widely studied, but the conclusions have been varied and
contradictory - they remain almost as much of a mystery today as
they did when Hippocrates carried out his research in ancient
Greece. Much of the mystery surrounds the relationship between
twins, and how this affects their lives.
It's a twin thing
There's no doubt that twins share a unique closeness - while
most of us spend our time in the womb in solitude, research shows
that twins begin to interact with each other from as early as 16
weeks gestation. The National Geographic documentary Inside the
Womb: Identical Twins shows fascinating ultrasound footage of twins
holding hands and kicking each other in what appear to be quite
deliberate movements.
Dr Alessandra Piontelli studied the
conduct of both twins and singletons in utero and concluded that
some twins appear to actively seek each other out, behaviour which
continues after birth. Let's face it - after nine months of
cohabitation in very close quarters, it's not surprising that twins
develop a strong bond!
However, while this closeness has
its obvious benefits - a constant playmate and source of
reassurance and support- it does also have drawbacks. Twins are
often described as having a love-hate relationship, and most
parents of twins would agree that their children spend a decent
amount of each day at war with each other.
Co-dependency is also a problem in some
twin pairs - sometimes the closeness of the relationship between
the twins leads to a mutual reliance on each other. This is not
helped by our societal perception of twins as a single unit.
Research has shown that young twins often identify themselves as a
single unit, and define their own lives by their twinship, a result
of being constantly labeled "The Twins". Evidence suggests that
this is more of a problem for identical twins, and to a lesser
degree, same-sex fraternal twins, than it is for boy-girl twins -
after all, we're not likely to mistake boy-girl twins for each
other, something which happens frequently for same-sex twins!
As twins grow older and begin to
explore their own identities, most are able to form healthy
relationships with others, but studies show that when asked who
their closest friend is, more than half of all adult twins still
name their twin sibling, even ahead of their spouse.
Does identical really mean identical?
Most of us are aware that there are two different types of
twins: Identical and fraternal. But what many people don't realise
is that while identical twins might look the same, they are each
complex and different individuals. Identical twins share the same
DNA profile, but each has their own fingerprints. They have the
same eye, hair, and skin colour, but the shape of their heads and
faces often differs as a result of the differing positions they lay
in inside the womb, and variations in the blood supply through each
twin's umbilical cord. They usually have similar IQs, but do not
necessarily have identical personalities - in fact, they are often
polar opposites. One twin may be left-handed, while the other is
right-handed, and although dressing identical twins in matching
outfits might be cute when they are newborns, by thetime they reach
preschool, they will likely be asserting their own individuality by
choosing to wear something different. As for telling them apart,
the myth that a mother can always tell her twins apart is exactly
that, a myth - in the haze of the early days, most twin parents
choose something more reliable than their own sleep-deprived brains
to distinguish their babies, such as an ID bracelet or
different-coloured toenail polish. As toddlers, identical twins
even have trouble telling each other apart - when they look in the
mirror, is it their twin staring back at them?
As they grow, the differences
become more obvious, but it's fair to say that even as adults,
identical twins often have to grin and bear it when mistaken for
each other. This does, of course, have its advantages - a pair of
twins in Germany recently escaped conviction for an aggravated
robbery because police were unable to determine which of them had
committed the crime!
Twin speak
It's generally accepted that twins are slower to acquire
language skills than singletons - around one child in 10 will
experience language delays, but this figure is significantly higher
for twins. On average, they are around six months behind their
singleton peers when it comes to speech milestones, but the reason
for this is unclear. Some experts believe that it is because they
develop their own private language, known as "twin speak", or
cryptophasia, and therefore don't need to learn conventional speech
at an early age. This twin speak may be the result of their intense
interpersonal closeness, or it may be simply a case of each twin
mirroring the other's immature speech patterns.
Twins also spend less time engaged
in one-on-one communication with their parents, and more time
communicating with each other during play, so it makes sense that
they understand each other's seemingly incomprehensible babble.
However, another explanation for this delay in verbal skills is
that twins are more likely than singletons to be born prematurely,
and to be low birth weights. Prematurity is recognised as a leading
cause of language delay in children, and the average twin gestation
is only 36 weeks, compared to 39 weeks for a single fetus
pregnancy.
Twin telepathy
We've all heard the stories of twins who can read each
other's thoughts, and who know when their twin is in pain despite
being on other sides of the country. Indeed, twin telepathy is one
of the most fascinating facets of twinship. One famous example of
apparent twin telepathy is the "Jim twins" from Ohio, USA.
Separated at birth and raised by adoptive families, both were
christened James, and when they first met each other in their early
40s, they discovered that they had both married women with the same
name, had named their children the same names, smoked the same
brand of cigarettes, shared many hobbies and interests, and had
parallel medical histories. While many of these similarities can be
dismissed as coincidence - for example, the name James was popular
at the time they were born - the sheer number of similarities lends
weight to the theory that the pair shared some kind of telepathic
link, despite being unaware each other even existed.
But can twins really read each
other's minds? To date, no scientific studies have proven the
existence of a telepathic link between twins, and anecdotal
evidence is far from reliable. Twins do demonstrate an uncanny
ability to know what each other is thinking, but those who have
studied twins and their behaviour believe that this is a result of
living closely with each other for an extended period of time, and
point out that twins score no better in telepathy testing than
siblings who have been raised together.
For every question that is answered
about twins, several more arise. After thousands of years of
exploration, it seems likely that research into the twin phenomenon
will continue to fascinate us for many years to come, and with the
rise in IVF and other assisted reproduction techniques, it seems
certain that there won't be a shortage of twins to study.
Emma Fahy is the former OHbaby! Web Editor and mum to
four girls, including three-year old identical twins, Sienna and
Mercedes, who hated being in the same bassinette as newborns, but
now fall asleep in each other's arms most nights.
As seen in OHbaby!
magazine Issue 9: 2010
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