Twins, especially identical twins, have fascinated humanity since the dawn of time. Sometimes twins are feared, sometimes twins are revered. Pre-colonial Brazilians thought twins were a product of adultery: often the mother of twins was executed. Some primitive African societies abhorred twins, because of the way multiple births resemble an animal’s litter; the unlucky children might be killed, the mother exiled.
Other cultures had more positive reactions to “identicals”. In Greek mythology, twins were the product of human intercourse with the gods: twins were therefore sacred. Ancient Slavs maintained that twins shared one special soul. The Yoruba of Nigeria were particularly obsessed, and believed that twins had magical powers, potentially bestowing health and happiness on a family.
Modern science has inherited this fascination. In 1875, Francis Galton (Charles Darwin’s cousin) published the first study on twin-ness, as a way of exploring heredity. His theories were embraced, and perverted, by the Nazis at Auschwitz. There they conducted cruel experiments on twins, in a fevered and doomed attempt to discern the “truth” of identicality. In recent years, kinder forms of science have studied twins, to broaden our knowledge of genetic traits, from intelligence to alcoholism (startling fact: if one identical twin has manic depression, the chances of the other suffering the same are about 60-80%).
And yet, despite all this interest, we remain mystified, emotionally and scientifically, by identicals. I know this because I recently spent a year researching a thriller, called The Ice Twins. And the deeper I dug the more I realised: we are only beginning to grasp how strange twins are, and, perhaps, quite why they interest the rest of us so much.
Take the vital question of identicality. Not all “monozygotic” twins (i.e. twins born from a single fertilised egg) are truly identical. Some are “mirror image” twins. This means that in one twin the hair might swirl clockwise, in the other twin, it will swirl anticlockwise: but it will swirl in exactly the same way. For one twin, the left side of the mouth might curve upwards, in the other twin, the right side of the mouth does precisely the same curve. This peculiar “looking glass effect” extends to the positioning of internal organs.
But many identicals are truly and purely identical, in ways we are still uncovering.
Obviously, identical twins share facial characteristics. And general size and body-shape. But they also share virtually identical DNA: meaning they are more closely related to each other than to anyone else, including their parents, or their own children. There are cases of twins being acquitted of crimes even when police have DNA evidence, proving that one twin is guilty. Because the twins share the same DNA, no one can be certain which of the twins has committed the crime.
And so it goes on. Identicals also share the same blood group, the same hormones, the same serum proteins; they are also alike in heart rate, blood pressure, brain waves, respiratory rate, and digestive process. They even breathe alike.
Such is the similarity of some identicals, hospitals commonly advise the parents to discreetly tattoo one twin, so that in future the children can be differentiated. Understandably, parents often refuse – believing they will be able to distinguish their twins as they age (not least, by dressing their kids differently). This, however, can be a mistake because twins often grow more identical over time (as their identical DNA asserts itself, following different levels of nourishment in the womb). And twins often end up being dressed in exactly the same clothes, anyway, lest one twin become jealous of the other getting “better” treatment.
Here we enter the peculiar world of twin psychology. Over recent decades, scientists like Thomas Bouchard (of the famous Minnesota Twin Research Center) have analysed the personalities of twins and discovered seriously uncanny facts.
Take the classic example of twins separated at birth. The extent to which they can echo each other in later life is breathtaking. One of my favourite cases is the separated twins who discovered, when reunited, that they both liked entering the sea, on beach holidays, by wading backwards up to their knees. Another, darker, example is the 72 year old twin brothers in Finland. In 2002 they were killed on their bicycles on the same road in northern Finland, in two accidents, just two hours apart.
Probably the most famous case of eerie identicality is that of Jim Lewis and Jim Springer. These identical American twins were separated when four weeks old, and adopted by different families in different parts of Ohio. When the Lewis-Springer twins were reunited at the age of 39, in 1979, they discovered that both of them were prone to biting their nails. Also, both of them suffered from tension headaches, both had worked as sheriff’s deputies, and both smoked Salem cigarettes. They also drove exactly the same kind of car and they both did serious woodworking in the garage.
And it didn’t end there. Both had been named James by their respective adoptive parents. Both of the twins had married twice. Both had married firstly to women named Linda, secondly to women named Betty. Both had produced sons named “James Allan”. Both had at one time owned dogs named Toy. And they both took their holidays at the very same beach in Florida.
Is this all down to genetics, and coincidence, and to similar environments in the womb? Scientifically speaking, it must be. Yet there are stories which could give a convinced materialist like Richard Dawkins pause for thought.
Some parents of twins have reported their children having identical dreams. Others recount twins suffering simultaneous pains, in the same part of the body. when only one twin is hurt. Doctors who observe twins in the womb have watched identicals do a strange kind of twin dance: the fetal twins come close to each other, face to face, then one of the twins makes a circle, and the other does the very same. It as if they are, in utero, telepathically aware of each other’s movements.
Even in grief twins possess an oddness which startles. Joan Woodward, in her study of twin bereavement (The Lone Twin) reports several striking examples of twin reaction to the death of a co-twin.
Some young twins simply do not believe the death, and continue to act as if the lost twin is alive (talking to the dead twin at breakfast, in a shared twin language, for instance). Other infant twins seem painfully confused as to whether their dead twin is really dead, because they keep seeing the living image of their dead sibling in the mirror, or in a reflecting window – when they see themselves, they see the sibling. By contrast, a few bereaved twin children deliberately seek out mirrors: to reassure themselves their dead twin lives on. They want to see the living ghost.
Other twins react differently still. Woodward records how some twins, following the death of a co-twin, take over their lost sibling’s characteristics, growing more like the twin that died, as if trying to make up for the loss by actually becoming the dead twin. One twin whose brother died at the age of 12 became so eerily like his dead sibling his parents were convinced he had the ‘spirit of his brother within him’. Another female twin who lost her sister was so grief-stricken she took her dead sister’s name, and abandoned her own.
These strange reactions, surrounding the deaths of identicals, can have affects beyond the twins themselves. During my research I came across one wholly remarkable example of twin confusion, following a death. It happened in California in the 1990s (though the details and names have been protected by authorities, for obvious reasons).
One day, driving off on holiday, the Andersons – father, mother and their twin daughters, Samantha and Katie – had a terrible crash. An ambulance was called and the victims were cut from the car. However, after reaching the hospital Samantha soon died, and Katie was left in a coma.
It was a horrific loss, but life had to go on. The family concentrated on their grieving, and with helping their surviving and hospitalised twin, Samantha, get over the death of Katie. A funeral for dead Katie was held at the local church.
And yet, as the surviving twin improved, the twins’ mother Sally found it strange that “Samantha” behaved so much like her dead sister “Katie”. Finally Sally studied her child’s birthmark very closely (the twins had similar but not identical birthmarks) and she realised a terrible mistake had been made – Katie had survived and Samantha had died. They had misidentified the dead twin. This realisation occurred two weeks after the accident and ten days after the funeral. The Andersons had therefore buried the “wrong” daughter. Now the dead daughter had come back to life. And the living daughter died all over again.
It was reading that extraordinary true life story – and all these other facts – that gave me the idea for a thriller. What would happen if the Andersons’ experience was repeated, but the family only discovered their error a year later? What ghostly consequences might ensue?
Whatever the answer: one thing I know for sure is that twins will continue to fascinate us, because they ask so many profound and unsettling questions. What is to be related? What is to be alone? When we are all so interlinked, can anybody be truly individual?