Twins: Genes, Environment and the Mystery of Identity 
by Lawrence Wright.
Weidenfeld, 128 pp., £14.99, November 1997, 0 297 81976 3
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Once upon a time, two identical twins were separated at birth; neither knew she had a twin. Years later, they chanced to be in the same place at the same time, and each was mistaken for the other, until they were finally brought together, all misunderstandings were explained, and everyone lived happily ever after. This is what I would call a myth: a story which people continue to believe is true in the face of sometimes massive evidence that it is not; a story that is told again and again because it poses a question that can never be answered. In this case: what is it that makes each human being unique?

The plot, a favourite in the folk tales and mythologies of many countries, was already so well known in ancient Rome that it was satirised in Plautus’ play, Menaechmi, in which one twin is mistaken for his brother by his brother’s courtesan. When the story is played as comedy, the joke lies in the fact that the double innocently and unintentionally takes over his twin brother’s life (or wife) and, idiotically, cannot understand why people keep thrusting it (and her) upon him. The Comedy of Errors, Shakespeare’s slapstick treatment of Plautus’ version (itself an imitation of a Greek original), has in turn been adapted in musical comedies such as The Boys from Syracuse and A Funny Thing Happened on the Way to the Forum. (Shakespeare also treated the androgynous variant in Twelfth Night, where a woman in drag is mistaken for her long-lost twin brother.)

The joke sours to tragedy when the double intentionally and malevolently usurps the identity of the twin, a common motif in novellas and films. The myth, tragic or comic, assumes that the twins appear to be alike but are in fact polar opposites in character (the switched sisters in the films Big Business, My 20th Century), class (The Prince and the Pauper, The Prisoner of Zenda), race (Puddn’head Wilson) or even species (Herakles and Iphikles, the immortal and mortal infant twins born of Zeus and Amphitryon).

Lawrence Wright grounds what he calls ‘this widespread fantasy’ in other peoples’ studies of separated identical twins:

Babies actually do get lost or separated, and, however rare such an event may be, when a person finds his twin it feeds the common fantasy that any one of us might have a clone, a doppelgänger; someone who is not only a human mirror but also an ideal companion; someone who understands me perfectly, almost perfectly, because he is me, almost me.

He returns to this theme at the end of his essay, imagining the lost twin as another individual ‘who is uniquely able to understand you’. Here, the story of twins shades into the romantic fantasy of finding a lover who is your unique other half, the myth of the androgyne (or male/male or female/ female couple) treated in Plato’s Symposium.

There may be an embryological basis for the myth of the vanished twin and for its psychological manifestation in the feeling some ‘singletons’ have of being incomplete. Apparently, many embryos start out as one of a pair, the other dying in the womb, often at a very early stage of development. The term ‘vanishing twin’ was coined in 1980 for a twin that dies in the womb and from whom, in that sense, the surviving embryo is separated before birth. The publication of evidence for this phenomenon has, predictably, inspired many people to claim to be survivors of vanished twins, a claim which has, equally predictably, inspired ‘psychotherapies designed to regress patients into the womb so that they can get in touch with their vanished twin’. Another mythical monster, the chimera (lion head, goat body, serpent tail) was evoked by the geneticist Charles Boklage to characterise the many ‘twins who are walking around in a single body’. These people, presumably, have recovered and incorporated their vanished twins, becoming atavisms of Plato’s undivided androgyne. Similarly, what Freud called the Family Romance is the myth of a child switched, rather than separated, at birth, who goes on to discover that he is his own non-existent, royal twin (Oedipus, King Arthur, Krishna).

Wright regards ‘mythologising’ as little more than ‘lying’: separated twins who overdramatise their resemblances, or make up stories in order to get into the press, are ‘mythologising’, a charge supported by the likelihood that ‘the press’ in this instance is the National Enquirer, the primary US supermarket-checkout source of contemporary mythology. But Wright understands the point of the ancient mythology – that there is a fundamental difference between the twins, and that what excites us is the fantasy of a ‘projection of ourselves living another life, finding other opportunities, choosing other careers, sleeping with other spouses … an identical Other who has lived a life, been marked by it, and become uniquely different from us’.

There is something endearingly American about this credo of self-creation; Wright continues: ‘We struggle through experience to build our character. Our task is to make ourselves unique … We become the people we choose to be; this is the premise of free will.’ This interpretation would probably not be shared by most of the cultures that have been fascinated by the myth, which generally assume that the twins are born different. The divergent interpretations, however, meet like twins in the same place, with the conclusion that, when they are reunited, they may still look alike, but they are, either from birth or from experience, different. Wright returns repeatedly to this theme, concluding: ‘After you’ve explored the variety of ways that you are alike, it is the differences between you that capture our attention. Perhaps that is a way of holding onto your separateness, your particular identity.’

Each time he tells the myth, however, his gloss shifts from the ancient to the modern variant, which emphasises not difference but similarity. Wright regards this as ‘a darker and more threatening side to the story’, which ‘may be the real secret of its grip on our imagination’: ‘If we discover that we are fundamentally alike despite our various experiences, isn’t there a sense of loss? A loss not only of identity but of purpose? We are left wondering not only who we are but why we are who we are.’ Again and again he comes back to the fantasy of the twins who in many respects ‘have become the same person’, and, in the modern variant, are ‘genetically identical’. Twins confound us ‘almost as if they were a divine prank designed to undermine our sense of individuality and specialness in the world’. Unlike the desired Other who shares our thoughts, this other ‘encroaches on our sense of being unique in the world, of having thoughts and desires and experiences that no one else knows or can possibly share’.

Why does he accept this twist? Why does he assume that the twins will turn out to be ‘fundamentally alike’, ‘the same person’, or that being ‘genetically identical’ means that twins will have ‘thoughts and desires’ in common? Because his interest lies not in myth but in science, the modern twin of myth, and the biobehavioural theory that drives contemporary twin studies favours the hypothesis that twins remain similar in different environments, and that this similarity constitutes proof, or at least evidence, that genes prevail over environment, that nature is stronger than nurture.

But the myth of twins loses its charm, to put it mildly, when it masquerades as science. As Wright admits, ‘It is certainly true that the history of twin research is one of the most appalling chapters in science, having been born in Galton’s aristocratic notions of the natural worthiness of the English upper class, taken to its evil extreme by Nazi eugenicists, and too readily used by American scientists to rationalise racial injustice.’

Francis Galton, Darwin’s cousin, had explicitly raised the question of nature v. nurture with reference to separated twins, in 1875, and in the Thirties and Forties, twin studies separated into the extremes of Fascism and Communism: on the right, Josef Mengele carried out sadistic and often fatal experiments on twins in Nazi camps; on the left, the theories of Lamarck and Lysenko, which argued that acquired characteristics could be inherited, i.e. that nurture could change nature, reigned over the Gorky Institute in Moscow (and dominated Soviet agriculture until they were discredited in 1964, after massive crop failures).

During the Sixties, in New York City, twins put up for adoption were separated and used for psychological studies under the direction of Peter Neubauer, who never told either them or their parents that they were twins, or that they were being studied. In our day, the political bias has resurfaced in the racist hypotheses and conclusions of Richard Herrnstein and Charles Murray’s The Bell Curve. One of the twins in Neubauer’s study later remarked, ‘This is nightmarish, Nazi shit,’ while the psychiatrist involved in the study confessed: ‘In those days we were playing God.’ Satan, I’d say, while we’re waxing mythological.

The centre for twin studies is no longer New York but Minneapolis, where the behaviourist B.F. Skinner worked, and where, since 1969, Thomas Bouchard has taught a course on the ‘measurement’ of individual personalities and twins. ‘Not every university offers such a course,’ Bouchard has remarked, ‘in part because race, gender and class differences are closely compared, which arouses passionate debate over whether such differences are genetic or environmental.’

Wright’s liberal sensibilities are appalled by what he thinks the twin studies prove. But why is he so easily persuaded? The issues are complicated by the genuine science which has been fostered by twin studies, and which has led, for instance, to the isolation of genetic factors in the incidence of certain diseases. It is when one moves from the relatively hard facts of biology to the more subjective data of psychology and sociology that the rot sets in. Claims of clairvoyance, ESP and telepathy pollute ‘twin lore’, and compound the ‘magical air’ produced by studies which seek to demonstrate effects without revealing causes. Indeed, the secrecy of the Neubauer project (which he never published) and Bouchard’s refusal to release raw research data, ‘citing privacy concerns on the part of the twins’, would alone invalidate the scientific status of their findings, even if all else were well. And it is not.

One major problem is that, although separated identical twins are compared with fraternal twins and with non-separated identical twins, they are not systematically compared with people who are not twins at all. How could they be? When we are told that the identical (and separated) twins, James Lewis and James Springer, had each married and divorced women named Linda and remarried women named Betty, we would need some kind of random sample of all the other people born on the same day (for instance) who married women named Linda and Betty – a cumbersome, if not impossible, project. As Bouchard admits,

The probability that two people have the same name can’t be validated against some random action. What you need is a population of couples the same age as the twin couples with their kids, and then you’d need to know the frequencies of all these names. Think of how much work you’d have to do to gather that kind of information – but then you’d have to do it for everything! About the car they owned! About the beach they went to! What they named their dog! You’d have to collect that data from every pair. And then, what would it tell you?

Yet Bouchard does not admit that the lack of such a control invalidates his research.

Even more significant is his acknowledgment that ‘you’d have to do it for everything!’ In other words, there are no controls on which factors are compared and which are not – on the differences that offset the similarities. Twins, for instance, never have completely identical fingerprints. Twin studies select factors out of an infinite variety. What features should they choose to test for similarity? Appearance, the (subverted) criterion of myths? IQ? Nose proportions? Or should they ask if the two women named Linda have the same nightmares, or make the same noises in bed? One particularly striking, and surely significant, difference is in sexual partners. Wright notes that, ‘although twins competing for the same mate is a staple of television talk shows’ – and, I would add, of myths – one study claims to prove that in real life identical twins don’t tend to be attracted sexually to the same sorts of partner: ‘The extraordinary difference between identical twins lies in whom they choose to marry.’ To question the selected criteria is to ask: how do you essentialise the person?

And there are so many jokers in the pack. Twins raised together often make a conscious effort to differentiate themselves, more than twins raised apart. On the other hand, identical twins raised apart may be treated similarly by their adoptive families because of their physical similarity (ugly ones teased, pretty ones praised etc). Then again, there is often a negative correlation between similarities in personality or ability: the twins who look most alike are least alike in their behaviour. Besides, the ‘separated’ factor is often corrupted by shared environments, always shared in the womb (prenatal influences) and often in early childhood, or by unrecorded meetings during the adult testing period. In the end, as Wright admits, we ‘must face the question of why identical twins should differ at all … The differences in identical twins may turn out to be more informative than their similarities.’

The conclusions drawn from the studies, and their recommended applications, are even more seriously flawed than the data. One of the Minnesota researchers, David Lykken, wants to prevent low IQ mothers from having children (to ‘reduce the number of low IQ children’). This is, as the twin studied by Neubauer so nicely summed up that project, more ‘Nazi shit’. ‘A lot of social scientists are so scandalised by my proposals that they think I must be a Fascist,’ Lykken himself has complained. Now, why would anyone think that?

In the view of Sandra Scarr, a colleague of Lykken, twin studies prove that ‘good enough’ parents (in Winnicott’s phrase) will have the same effect on their children as ‘superparents’. Her claims have been attacked by ‘some developmental psychologists and others’, who believe that they ‘discourage efforts to improve the welfare of children – especially black children – and fail to hold parents accountable for their children’s behaviour’. Twin studies appeal to a large segment of the population who have no racial axe to grind: to parents who wish to be absolved of guilt for the shortcomings of their children, a group that probably includes all parents at some moments in the long haul of childrearing. Racists, Nazis, Communists and guilty parents form an uncanny and unholy alliance. Wright notes that to give in to these views, to cease to struggle to control our environment, is to yield to ‘a kind of social and political nihilism which says that there is very little we can do to change individual lives. Carried to an extreme, this view of human development suggests that the best, and perhaps the only way of improving society is by manipulating the gene pool.’

This view is unjustifiably fatalist, assuming, for instance, that a person with low IQ is ineducable. But statistics about people cannot be interpreted or applied like statistics about potatoes. Twin studies attempt to quantify the non-quantifiable aspects of human nature. Few of us would deny that a child is more likely to have a rough ride through life if she is born of a mother addicted to crack. But if even one such child thrives, all bets are off. And what do we mean by ‘thrive’? How do we factor into these data the triumph of overcoming adversity, the achievement born of disability, the Helen Kellers, Christie Browns, Franz Rosenzweigs? Until the statistics are 100 per cent, each individual has the right to hope that she will be the exception, but an exception is a human phenomenon that is steamrollered by the biogenetic argument. Statistics factor out the ability to fight against our natures; freedom, as one geneticist suggests, is ‘the ability to stand up and transcend the limits of the environment.’ Moreover, until we know what it is to be a good human being, how can we engineer one?

Twins are Rorschach tests: we read into them whatever we want to prove. Why have twin studies therefore so often been applied to racist ends? The fact that twins look alike – their uncanny sameness – may attract the attention of people who think that all the members of certain classes or races or genders are alike. (Indeed, some ancient variants of the twin myth, like their modern scientific descendants, privilege one class or race over another – the black swan that secretly replaces the white swan, the prince and the pauper). Who is doing this research? Twin studies, and related genetic projects like The Bell Curve, have largely been funded by the Pioneer Foundation, whose racist agenda was convincingly exposed by Charles Lane. The fact that twins come in twos may also have attracted people in thrall to the dichotomy of genes v. the environment, a dichotomy enshrined in the title of Wright’s book (the title of the American edition is less controversial, more psychobabbling – Twins: and what they tell us about who we are). Wright hopes that ‘the reader will forgive the obvious analogy that genes and the environment are like conjoined twins, distinct but inseparable.’ What a pity that twins have been chosen rather than triplets (rarer, of course), for the study of triplets might have generated different paradigms, perhaps more Hegelian, certainly more diverse.

Why not just demonstrate that some factors owe more to nature, others to nurture, and leave it at that? Because such an argument lacks the sharp edge that is the weapon of ideology. Humanistic studies of twins are not statistical but anecdotal, a dirty word in the laboratory. But since twin studies take place in an area in which rigid statistical controls are impossible to maintain, all of them are ultimately anecdotal – indeed, mythological. Wright’s book is full of fascinating anecdotes – which prove nothing but the selection criteria favoured by the researchers. Their studies fail not (only) because they do not, and cannot, establish reliable scientific controls, nor even because they are asking the wrong questions, driven by corrupt political agendas, but because they either forget or assume that they already know the answer to the question that gives perennial life to the myth of the separated twins: what is it that makes every human being unique?

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Vol. 20 No. 9 · 7 May 1998

Reviewing Lawrence Wright’s book Twins, Wendy Doniger (LRB, 19 March) referred to my work and states that ‘twins put up for adoption were separated and used for psychological studies.’ This ambiguous phrase easily leads to the conclusion that the twins were separated so that a study could be undertaken. Wright’s account makes it perfectly clear that it was the adoption agency that decided to separate them, following the belief at that time that twinship is a burden. The agency treatethe twins no differently from other siblings, who were also separated into different adoptive homes. It was only after I was informed about this policy that I organised a unique prospective study of these twins. Our focus was to explore the effect of environment on development. Doniger quotes one of the twins who remarks that ‘this is nightmarish Nazi shit.’ He, too, mistakenly assumed that he was separated in order to be studied, an assumption fashioned by the press to dramatise the issue. Doniger states that neither the twins nor the parents were told that they were being studied. This is not true. It would not have been possible to visit them at regular intervals, to observe and test them, to interview parents without their knowledge. I have also never expressed the opinion that we were ‘playing God’. This again was a statement made by members of the media.

Doniger writes: ‘Why not just demonstrate that some factors owe more to nature, others to nurture, and leave it at that?’ But this would impose an unacceptable restriction on research. It is the obligation of researchers to figure out the specific area of influence of both heredity and environment.

Peter Neubauer
New York University

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