The Puzzle of Left-Handedness (30 page)
So there we are. By this route we get exactly the right number of left-handers and the right number of monozygotic twins, along with an explanation for the fact that the frequency with which they occur in all population groups is stable. All this is based on just one assumption, namely that both phenomena are caused by the splitting of embryos at an early stage. The rest of the facts I have drawn upon here are well known from experience and research. Moreover, in this theory hand preference arises from a mechanism that we know causes other reversals, rather than from a special gene variant assumed to function purely as a factor that causes a switch in hand preference.
Nevertheless, we cannot prove this is how left-handedness arises. We’ll have to leave that to the embryologists.
There are a few fuzzy edges left. It’s no simple matter to explain how parental influence works. If the tendency to split is generated by signals from the mother’s body, how can the father contribute to it? Further research is needed into the mechanism involved. Entirely left-handed couples are relatively rare, so impressions may be misleading. There’s also a need to examine whether in the case of mixed couples it indeed makes no difference which parent is left-handed. As far as I know, there have been no systematic studies on the subject. It would be far from surprising if the mother’s influence turned out to be greater.
A second loose end is the question of why it should be that we are all essentially right-handed by nature and not left-handed. The best explanation on offer is William Calvin’s story about the reassuring sound of a mother’s heartbeat, which is not altogether satisfying.
Finally there are dizygotic twins, who also have increased rates of left-handedness. We cannot solve that one, but perhaps we can lay it aside as less than wholly relevant, since dizygotic twins are far more common in some population groups than others. This suggests there may be no direct connection between the occurrence of non-identical twins and the occurrence of left-handedness. A small proportion of the increase in the likelihood of left-handedness can be attributed to trauma. Twins are squeezed together in the womb and often born prematurely or by artificial means. If they are not delivered by caesarean section then one of them always has to wait its turn, with all the attendant risks, of oxygen deprivation for instance. Who knows, perhaps the fact that over the past few decades a great many dizygotic twins have been conceived with the aid of technical interventions of one kind or another is a relevant factor.
As far as the causes of left-handedness are concerned, the ball is back in the researchers’ court. Until we have more data about the theory posited here, there’s little more to be said. It’s therefore high time to look at the consequences of left-handedness, in all their many shapes and forms. Some are real, some imagined, some pure fantasy, and they range from the innocent or merely odd to the thoroughly disadvantageous.
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The Consequences: Contrary, Perverse and Sick
‘Gene for left-handedness is found’, ran a
BBC
News headline on 31 July 2007. It went on: ‘The Oxford University-led team believe carrying the gene may also slightly raise the risk of developing psychotic mental illness such as schizophrenia.’ But left-handers shouldn’t worry, the leader of the study reassured the public, since ‘the vast majority of left-handers will never develop a problem’. Just how large that majority was, the news item did not say.
The ease with which such announcements are made is bizarre. No soup manufacturer would ever dare to put out a press release saying ‘unfortunately, small splinters of glass have been found here and there in our tins of soup, but don’t worry, the vast majority of consumers won’t even notice’. Journalists would make mincemeat of the soup company boss, as would customers, food safety inspectors, politicians and the courts.
The same year further alarming reports emerged, this time from Australia, where a large-scale study had shown left-handed toddlers to perform considerably less well in every respect than their right-handed contemporaries. They also spent less time on educational activities and far more watching television. Scores were even lower for children without any clear hand preference. They were said to suffer from ‘hemi spheric indecision’. The researchers conceded that this last finding might arise in part from the fact that some pre-school children do not yet show a definitive preference for either hand, but they were nevertheless happy to declare that neither left-handedness nor mixed-hand ed ness augur well.
At the same time they made mention of what might be called the most curious piece of research of the early twenty-first century, carried out at the renowned Johns Hopkins University in Baltimore, which concluded that highly educated left-handed men in America earn an astonishing 15 per cent more than their right-handed colleagues. Their enviable advantage was predictably hard to explain. It remains unclear, the American researchers said, ‘whether left-handed graduates earn more because they perform better on the labour market or because they more often choose a more ambitious course of study and are more successful at it’. Either way, their findings were incompatible with the alarming developmental lag found in those 5,000 Australian toddlers. Falling behind and underperforming won’t set you on the path to becoming an overachiever.
Equally strange is the fact that no one has detected such divergent outcomes anywhere else. If left-handers really do perform so poorly and have so many problems, then special education establishments, child welfare bureaus and youth detention centres ought to be overflowing with them. Which they are not. If left-handers really do earn so much more on average, wouldn’t an aggrieved right-handed majority have rebelled against this injustice long ago? That hasn’t happened either. In fact in everyday life no one seems to have realized how extraordinary and even dangerous left-handers are.
Fortunately, left-handed people don’t usually pay much attention to dramatic announcements of this kind. They’ve grown accustomed to a great deal along these lines, most of it heard once and never again. Of course if three left-handers meet in a bar – a likelihood of one in a thousand, so it doesn’t happen to them every day of the week – then they may perhaps briefly wallow in resentment towards the short-sighted educationalists who unnecessarily blighted their childhoods, but that usually exhausts the topic. Left-handers have no desire to adopt all-out victimhood. Shops selling left-handed items usually struggle to stay afloat – the British online store Anything Left-Handed being the exception that proves the rule – and most attempts to organize seem destined to fail. Only the United States turns out to be large enough to sustain a Lefthanders’ Association.
This is not to deny that left-handed people frequently find themselves confronted with the consequences of their aberrant hand pref er ence, but their difficulties are generally of a quite different order from those the right-handed imagine to exist. Moreover, consequences are not always disadvantages but may sometimes work in the left-hander’s favour, and where problems do arise they’re often less serious and easier to resolve than the average right-hander might think. Right-handers often watch left-handers the way an audience watches an illusionist sawing a lady in half: you don’t need to be told that you shouldn’t try this at home. The left-hander, like the illusionist, is a specialist in his field. Nature has given him more talent in his left hand than any right-hander can boast, and since early childhood he’s found ways of dealing with a world full of right-handed people. The lasting impact of an outside world that from time to time thwarts him and the greater flexibility he’s forced to adopt seem, at least, to cancel each other out.
Although we have plenty of preconceived notions about left-handers, there’s no such thing as serious ‘leftism’ – or should that be ‘rightism’? – and prejudice against left-handers has few practical consequences outside school. Nevertheless, it’s infuriating, even downright dangerous, that scientists of fame and repute heedlessly contribute to their perpetuation. They make it extremely tricky to find out whether left-handedness really does have physical or mental consequences, as well as perpetuating the risk that people will wrongly be seen as suffering from some kind of disorder, or even written off by society as somehow inadequate. Abram Blau tried exactly that, as did Cyril Burt and more recently the Canadian scourge of left-handers Stanley Coren. Early psychoanalysts too, such as Wilhelm Stekel and Wilhelm Fliess, followers of Sigmund Freud who loved playing around with symbols and old popu lar maxims, laid themselves open to much criticism on these grounds.
In the early years of the twentieth century Stekel claimed that in dreams ‘left’ symbolized crime and therefore indicated homosexuality, incest and perversion. Fliess went even further: he transposed Stekel’s dream theory to the real world and added to it the ancient connection in folklore between the left and the feminine. ‘Where there is talk of left-handedness,’ he pontificated, ‘the disposition that belongs to the other sex is more in evidence. Not only is this verdict always correct, the reverse is also the case: when a woman seems like a man or a man like a woman, we see an emphasis on the left side of the body. Now that we realize this, we have the magic wand in our hands that allows us to discover left-handedness. This diagnosis is always correct.’ Even that wasn’t enough for him, since the combination of what he regarded as male and female qualities amounted in his view to degeneracy. It therefore didn’t surprise him at all that there were ‘so many’ left-handers to be found among criminals and prostitutes. He went ahead and published without making the slightest effort to verify what he was saying, and without giving any thought to the consequences this kind of piffle might have for left-handed people in the sexually repressed society of his time – and indeed the effect on homosexuals of yet again being lumped together with criminals. Freud was enthusiastic about his good friend Fleiss’s ideas about bisexuality and the combination of male and female sexual dispositions, but to judge from a personal letter he sent in response, he was less charmed by talk of a connection with any particular side of the body. Nevertheless he did not feel it necessary, then or later, to distance himself publicly from Fliess’s pronouncements.
The worst thing about pseudo-scientific fantasies of this kind is that they are put forward by gentlemen of repute who present themselves as scientists, as people making a sincere effort to gather knowledge that everyone can rely upon. After all, that’s what being a scientist is all about.
Most people involved in scientific endeavour don’t act irrespons ibly, but the influence of thoughtless clichés and deeply rooted mythology remains appreciable. This is demonstrated most plainly of all by the ubi quitous tendency to regard left-handedness as a problem. Dispro portionate attention is paid to any association between it and specific ailments and disorders, while other possible side-effects of left-handedness are ignored. This has resulted in a gradual emergence of the idea that every left-handed person must have something wrong with them, even though on closer inspection there’s little basis for any such conclusion. Of course there are left-handed people who suffer from dyslexia, hay fever, stuttering, personality disorders, retardation or whatever you care to name. Among people with some of these disorders we do find more left-handers than would be expected based on their share of the population alone, but the connections are weak and the overwhelming majority of left-handed people suffer from none of these things. We don’t know whether there are any links between left-handedness and characteristics that in no way constitute a handicap. With a handful of exceptions, no one has ever tried to find out.
Research that focuses lopsidedly on associations with health risks creates an unjustifiable impression that left-handedness points to a poor state of health. There are no grounds for any such conclusion, as Norman Geschwind demonstrated by way of the following example. Women in the modern Western world run a considerable risk of a range of serious illnesses that do not occur in men. Think for example of cervical or ovarian cancer. Pregnancy and childbirth are also reserved exclusively for women and despite all the care available nowadays they are still not risk-free. Yet women of all ages have lower mortality rates than their male contemporaries, because the risks they face are more than counter-balanced by a reduced likelihood of other, often fatal afflictions like heart attacks and lung cancer.
When it comes to left-handedness specifically, the prognosis for schizophrenic twins is as clear-cut as it is puzzling. The sufferer will be considerably better off if at least one twin is left-handed, and it needn’t even be the schizophrenic one.
There’s as yet no reason to assume that left-handed people in general differ very much from the rest of us, either physically or mentally. If there is a difference, then it’s too small for us to draw any conclusions about a person’s state of health based on his or her left-handedness. That would be as absurd as to look at a man who is bald and conclude that he’s being treated for cancer, or being poisoned with arsenic by his wife, even though both could certainly lead to hair loss.
Perhaps all we can say, intuitively, is that left-handers are on average somewhat less sociable and slightly more headstrong than normal, although we have no proof even of this. Those characteristics have no essential connection with the left hand, but left-handers learn even during their first attempts to tie their shoelaces that they will have to stand on their own two feet rather than simply copying everyone else. Left-handed people always have to do something extra, reversing the procedure demonstrated to them. Right-handed children never have to do this, except in those rare instances where both parents are left-handed. Even should they want to, most right-handed parents and teachers are simply not in a position to demonstrate a left-handed way of carrying out everyday tasks. They are generally content to be able to tie their laces and neckties at all – and who could blame them?
In any case, it’s not at all easy to make yourself aware of all the things that can be done either left-handedly or right-handedly, since basic manual skills tend to come naturally to us. Only left-handed people notice the difference, consciously or unconsciously, and look for solutions of their own. They usually find them pretty quickly. The result is that they remain inconspicuous, so other people take little account of their unusual hand preference.
So we come full circle. From an early age left-handers are forced to be slightly more self-reliant than average. That won’t do much to engender meekness in them.
