by Rik Smits
The overwhelming majority of people are either left-handed or right-handed to a significant degree, even if they do not use their preferred hand for every single task. Truly ambidextrous people are extremely rare.
Michelangelo could, apparently, which gained him a reputation for being ambidextrous. The painting of the ceiling of the Sistine Chapel in Rome was not merely an artistic tour de force, it was a physical one as well. For much of the time he had to lie just under the roof, on high scaffolding. Anyone who has installed a light or mended a hole in the ceiling will have some inkling of what it means to work for long hours, day after day, with your arms raised. Gravity and lactic acid soon make the muscles weak and painful. It’s possible the world-famous painting might never have been completed if the artist had not been able to switch from one utterly exhausted arm to the other, but this does not tell us whether Michelangelo was truly ambidextrous. To find that out we would need to know whether he always started the day using the same hand and which of the two he used under normal circumstances, back in his studio. We might not be much the wiser even then, since according to contemporaries Michelangelo was a left-hander who’d been taught to paint and draw with his right hand.
Opinions are deeply divided as to the true proportions of left-handed, mixed-handed and right-handed people. This is mainly because there are almost as many ways of measuring hand preference as there are studies of the phenomenon – and fault can be found with almost all of them. The simplest method would seem to be simply to ask people which hand they favour for certain tasks, but that will render up reliable data only if we can resolve three problems faced by the questioner. Firstly, nice people – which generally includes those willing to take part in research without being offered any significant reward – like to give socially desirable answers. In other words, they try to answer in a way that fits in with their ideas about how they ought to behave, rather than according to the facts of the matter. This tends to produce conformist answers that may not be true.
The second problem appears to contradict the first. Nice people have an equally strong tendency to try to avoid disappointing the poor researcher. They’re eager to tell the questioner something interesting, and this tends to produce non-conformist rather than accurate answers. The third problem is that people sometimes have no clear idea which hand they favour for certain tasks and so, entirely in good faith, they answer incorrectly.
It seems as if everything conspires to make the number of true answers as small as possible. This has nothing to do with the subject itself; these are problems that plague all pollsters and they help to explain why political polls can be so misleading. People want both to fit in and to tell the questioner what they think he’d like to hear, and they are only partially aware of their own actions and motivations. As a result, completely unintentionally, they come up with patent untruths. If you think this cannot possibly apply to you, just consider whether at this moment you could say with certainty in which position you are usually lying when you wake up in the mornings, whether you generally cut the toe-nails of your right or left foot first and which ankle goes on top if you sit cross-legged.
A radical way of avoiding the pollsters’ problem is to ask nothing at all but to take objective measurements. One approach has been to measure the strength of the grip in each hand, with the idea that the stronger hand would be the one a person truly preferred. A man called Jules van Biervliet tried an even more subtle approach in 1897. He hung equal weights on the index fingers of both hands of his subjects and asked which was heavier. If an individual said the weight on his right finger was heavier, then he was left-handed and vice versa. Others have used all kinds of methods of measuring the size of the hands and arms, labelling the larger as the one the subject favoured.
This approach allows us to say something about people who are long dead, based on their skeletons. In 1995 researchers at the University of Southampton and English Heritage’s Ancient Monuments laboratory believed they had found evidence that the proportion of left-handed people was slightly higher in the Middle Ages than it is now. They measured the lengths of the bones in the arms of 80 peasants who were buried between the eleventh and sixteenth centuries in the graveyard at the village of Wharram Percy in Yorkshire. In 16 per cent of skeletons the left arm was longer than the right, in 3 per cent both were of equal length and in the remainder the right arm was longer. Based on the assumption that the dominant hand is more often used for carrying loads, and that the right arm would therefore become slightly longer, they concluded there were more left-handed people around in the past than now. The reason for this, they believed, was that in an illiterate world there would be less cultural pressure to be right-handed. It was a story no less muddled than it was entertaining, since cultural pressure has never been about carrying loads but instead relates to things like writing and table manners.
A huge number of carelessly designed studies of this kind have been carried out over the years, all involving the assumption that the preferred hand is the one with which we perform best in certain circumstances: exert the most force, perform the quickest moves, carry the heaviest weights or detect the most subtle distinctions. But whatever they did, the researchers came up with different figures every time, and no wonder, since power and speed are not what hand preference is all about. A few top tennis players aside, our favoured hand or arm is not noticeably stronger than the other, and the cause of hand preference does not lie in the hand or arm anyhow but in the brain, an organ that until recently divulged virtually none of its secrets.
It is therefore more helpful to record behaviour than to look at physical characteristics. After all, the way we behave is the externally visible result of how our brains work. Even this approach is not without its problems, since social and cultural pressure mean that to some extent naturally occurring left-handedness is repressed, as we see even in the tolerant Western world of today when a child learns to write. In a busily scribbling school class there are even now slightly fewer left-handers on show than are present in reality.
This creates a need to look at criteria that are independent of culture, at tasks that are performed with the preferred hand but not governed by etiquette. Back in the 1930s, American Ira S. Wile came up with a truly original solution. He calculated the percentage of left-handers based, among other things, on people he counted as they passed a busy street corner carrying an umbrella or a shopping bag. If they were using their left hands, he categorized them as left-handed. Otherwise he ticked the box for right-handedness. The idea is not entirely absurd, but in practice it was undermined by Wile’s inability to control the circumstances under which he took his measurements. A person may carry an umbrella in his left hand because he’s left-handed, or it may equally well be because his right arm is tired or aching, because he’s injured his right hand, or for a thousand other reasons that Wile could not possibly know about. No wonder he arrived at one of the highest scores of all time: almost a third of the people in Wile’s research were left-handed according to his criteria.
If the results are to be valid it’s essential to exclude the possibility that people will display a particular behaviour for reasons other than those assumed by the researcher. This explains why psychological experiments usually take place in bare, utterly boring rooms and subjects are asked to carry out minor, often apparently pointless tasks. The fewer external influences at play the better.
Since observing behaviour in controlled circumstances is a time-consuming, complicated and expensive business, most researchers have fallen back on questionnaires. Any number of lists of everyday activities have been compiled, tasks that intuitively seem connected to hand preference: drawing, opening bottles, carpentry and so forth. But each study has used a different list, groups of subjects were by no means always a representative cross-section of the population, and each researcher evaluated and processed the data in his or her own way, so the results remain unreliable and comparison between them is problematic. Furthermore, in most cases l
ittle or no account was taken of possible taboos against left-handedness in the subject’s home environment. These problems still dog research today, even though standardized lists of questions have been produced, such as the Dutch Handedness Questionnaire compiled by cognitive psychologist Jan van Strien, all of them carefully assessed and judged capable of producing reliable data.
Putting the shortcomings of this motley array of studies into hand preference aside, several firm conclusions can be drawn. Left-handedness is slightly more common in men than in women and twins are rather more likely than other people to be left-handed. Race is not a factor, it seems, even though some studies, mainly from Africa, suggest that in black communities the proportion of left-handers is extremely low. Those particular studies all concern cultures that have a powerful taboo against left-handedness, and the low percentages are not replicated in research among the African-American population of the United States. This raises a further question: how do we explain the fact that a human characteristic occurs down through the centuries, all over the world, in a consistent minority of people of around 10 per cent and slightly more often in men and in twins? Then there is the remarkable fact that time and again we find more left-handers than normal within groups of people with problems and ailments of various kinds, whereas the opposite is never the case. Take a random sample of the population and there’s not a single characteristic, circumstance or disorder that can be shown to coincide with left-handedness. Most puzzling of all is the influence of age: the older the people questioned, the less likely they are to say they’re left-handed. Before returning to these mysteries we need to look at a question we all too often neglect to ask: what exactly does hand preference involve?
13
The Heart of the Matter
One day in the final weeks of the twentieth century a piano recital took place at the Max Planck Institute in Nijmegen, the Netherlands, and almost all the researchers working there came to listen. Such a frivolous use of precious time was almost unprecedented at the institute, but this was no ordinary recital. Pianist Chris Seed had travelled from England along with his instrument. Seed is a left-hander, like many other pianists, but unlike them he had acted upon a desire to play the piano left-handed. Before he began his performance he explained that this had ultimately resulted in the commissioning of a unique instrument, a pianoforte in reverse, modelled on an early form of grand piano from 1826. It was a faithful copy, except that the long bass strings were on the right while the high notes were hit with the keys on the left.
At first Seed found it far harder to learn to play the instrument than he’d expected. It seemed as if he’d have to begin learning again from scratch. But once he got going, Seed’s brain turned out to be perfectly capable of converting everything he’d ever learned into a left-handed playing technique. Exactly what he’d hoped happened: all the pieces of the puzzle fell into place more or less automatically. Seed became at least as good a pianist as he was on a conventional piano and eventually he felt real delight in playing ‘as God intended’. The audience, inquisitive and expectant, listened politely and watched with fascination as Seed took his seat at the keyboard.
Then something happened that was in no way exceptional.
Seed played the piano. He played excellently, perhaps even better than on a normal keyboard, although his audience was not in a position to judge. To the initiated it looked a little odd at first, with the pianist appearing to move in the wrong direction, but everyone grew used to that within a few minutes. In every other respect it was purely and simply a piano recital. Why would anyone expect anything different? This was a perfectly normal result, achieved while allowing for a hand preference that differs from the norm.
What then is the preference to which the term ‘hand preference’ refers? What is the heart of the matter? Of course we feel better and more comfortable when using our favoured hand, and there are many things that with the best will in the world we cannot do the other way around simply on command. But why is that exactly? It’s clearly not a matter of strength. Nor is it a matter of ingrained habit, since research using limb movement meters shows that people do not use their favoured hand appreciably more frequently than the other. It doesn’t even have much to do with dexterity. A classic test of hand preference, for example, measures how quickly a person can stick pegs into a perforated board. This turns out not to be a good way of telling whether a subject is right-handed or left-handed. Or take a normal right-handed violinist. The nimble dance across the fingerboard is always performed with the left hand, while the favoured hand only has to sweep the bow back and forth. The same applies to guitarists. The left hand dances across the six strings, faultlessly creating the most complex chords, while the favoured hand simply strikes them. Strumming and plucking may be intricate when we play classical guitar, but in pop music they amount to little more than raking the strings with a plectrum. Only in the case of the piano do we see what we might expect: the right hand performs the dextrous melodious work, the left the accompanying, usually simpler bass line.
Rudolf Kolisch (right) with his ensemble.
Nevertheless, a left-handed guitar player will quite often play a guitar that’s been stringed the other way, or even an instrument specially developed for left-handers, and most of those who make use of the alternative options are pop guitarists, like Jimi Hendrix, Paul McCartney and Bob Geldof. With violinists, who generally play in groups, bows poking around in different directions would be downright dangerous. Admittedly, left-hander Charlie Chaplin used a left-handed violin, but he didn’t play in an ensemble and he wasn’t a professional violinist. The only known case of a professional musician playing a violin with the strings reversed is that of Austrian Rudolf Kolisch, who died in 1978. It does seem, incidentally, that would-be violinists who are left-handed pay a price. No one ever mentions it, but music teachers, when asked, say they ‘have trouble with left-handed pupils’ and are under the impression that they’re more likely to give up. Left-handed professional violinists complain slightly more often about problems with the left wrist, which can become strained.
Among pianists the size and weight of the instrument stands in the way of left-handed playing. They do not usually haul their own pianos around with them. Nevertheless, Seed is not the first to have played a left-handed piano. Back in 1879 the Paris company Les frères Mangeot launched its piano à claviers renversés. It was a monstrous lump of an instrument: two grand pianos, one on top of the other, the upper a mirror image of the lower, put together in such a way that the two keyboards were stepped back like those of a church organ. It could therefore serve as a left-handed piano, although the main idea was that the pianist would no longer have to make great leaps from one end of the keyboard to the other and could use the same fingering for either hand. It was not a success. Since 2001 the renowned German firm Blüthner has been manufacturing its Model No. 4, a left-handed upright piano, but such instruments are still extremely rare.
The piano à claviers renversés, built by Les frères Mangeot.
Even though the vast majority of left-handed pianists play in exactly the same way as their right-handed colleagues, here lies the key to what hand preference really means. There’s an enormous difference between what a pianist is called upon to do and what a violinist or guitarist does. A pianist uses both hands to do roughly the same thing: strike keys. It’s usually necessary to strike them harder and more quickly at the high end of the sound spectrum, which is why a normal piano is designed so that the right hand has the more difficult job, but the point is that in theory the two hands work independently of each other. Were that not the case, Maurice Ravel’s Concerto for the Left Hand could never have existed. Ravel was commissioned to write the piece by a brother of the world-famous philosopher Ludwig Wittgenstein, Paul, after he lost his right arm in the First World War. It has to be said: with the help of Ravel’s genius it’s astonishing what a one-handed pianist can achieve.
Had Paul Wittgenstein been a violinist or guit
arist, no concerto would have been written for his left hand. He would have been unable to produce a simple children’s song, even a single note. Such instruments require the two hands to perform quite different tasks, complementing each other like Yin and Yang, combining to create the sound.
The positions of the fingers on the fingerboard of a stringed instrument are not greatly different from the fingerings on the keyboard of a piano, which every pianist learns to perform well with either hand, after a little practice. The fact that in the case of the violin and guitar we always leave the job of fingering to the non-favoured hand shows that in our apparently simple strumming and bowing lies something that makes considerable demands. It must have to do with rhythm, and with having complete mastery of the dynamic. It’s not a matter of strength but of control, of minimal, extremely precise differences in the force, pressure and speed of movement. Strumming and bowing involve exceedingly subtle steering.
With this in mind it becomes clear why people perform other tasks in which control and precision are important better and more easily with their favoured hand. Snooker players, for example, use their preferred hand to strike the ball, even if they have to tie themselves in knots to do so. The reason is not that they are required to hit it hard but that they must shoot with supreme accuracy, not only aiming perfectly but using precisely the right degree of force and ensuring that the cue doesn’t move so much as a millimetre too far. The ball must be knocked forward, not pushed away. Even when doing something as banal as sweeping the floor, we almost all use our non-favoured hand, low down on the broom-handle, to achieve a relatively crude thrusting motion, while the favoured hand is held loosely at the top to guide the broom and pull it back at the right moment.