by Martin Lasden
THE LEFT-HANDER SYNDROME by.
The Free Press, $24.95.
FOR REASONS yet to be fully understood, one out of every ten human beings in the world is left-handed, and from one generation to the next this ratio is roughly preserved. As we know, left-handedness cuts across socioeconomic, ethnic, and gender lines. Yet throughout history prominent figures in science—to say nothing of religion—have identified in left-handedness signs of depravity or worse. Consider Cesare Lombroso, an Italian physician who became famous for his theory of innate criminality. In 1903 he identified left-handedness as “one of the degeneracy signs of the born criminal.” Three years later Dr. Wilhelm Fliess, a friend and colleague of Sigmund Freud’s, suggested that left-handedness was a reliable indication of homosexuality. And in 1937 the British psychologist Cyril Burt declared left-handedness to be “a mark of an ill-organized nervous system.”
As demonstrated by all the “therapeutic" coercion that left-handed children were subjected to during the first half of the twentieth century, these biases had more than just a theoretical impact. Yet even when the gauche predilection was being discouraged, handism was certainly never taken as seriously as racism or sexism now is. Perhaps it’s the arbitrary nature of the trait that has militated against meaningful discrimination. After all, even when both parents are righthanded, there is still a 10 percent chance that they will bring a left-handed baby into the world. Moreover, a white baby born in Scarsdale is just as likely to be left-handed as a black baby in Harlem. Hence when the lefthander George Bush became President of the United States, it was hardly interpreted as a blow against bigotry. Nor was much attention paid to the fact that Ronald Reagan and Gerald Ford were also southpaws.
Which makes the latest news about left-handers seem all the more ironic. For while we’ve entrusted the country to lefties without thinking much about it, a consensus has quietly crystallized among those who have systematically studied the phenomenon that lefthanders as a group are more likely than the rest of us to suffer from a wide range of physical and emotional problems. The evidence comes in the form of well over a hundred studies published in medical and scientific journals during the past twenty years. These studies include one published in the Proceedings of the National Academy of Sciences in 1982, which shows that lefties are twelve times as likely as righties to suffer some learning disabilities, and ones published in Military Medicine and other journals in the early 1980s, which show that lefties are three times as likely to suffer from alcoholism, and that among treated alcoholics the relapse rate for left-handers is three times as high as it is for right-handers. There are even several studies suggesting that left-handers are significantly overrepresented in prison and delinquent-children populations. Lefthanders also show unusually high frequencies of depression, drug abuse, bed-wetting, attempted suicide, epilepsy, lower-than-normal birth weight, sleeping disorders, auto-immune diseases, homosexuality, and schizophrenia.
One would think that this much smoke would indicate some fire. But it wasn’t until two psychology professors— Stanley Coren, of the University of British Columbia, and Diane Halpern, of California State University at San Bernardino—conducted a study of 2,271 deceased professional baseball players that the debate over handism started heating up. The reason: Coren and Halpern found from their sample of baseball players that left-handers seem to live significantly shorter lives than their right-handed counterparts. In fact, they found that after age thirtythree the number of lefthanders who died in any given year was two percent higher than the number of right-handers, which over time translated into a fairly substantial discrepancy. Indeed, although the oldest lefthander in the study lived to age ninety-one, the oldest right-hander made it to 109. Coren and Halpern published these findings in the British science journal Nature in 1988, and soon after were bombarded by requests for interviews. At the same time, they started to receive a few unpleasant calls. “You right-handers think that you’ll live longer than us left-handers,” one anonymous caller told Coren. “But you won’t if we kill you first.”
So far these threats have amounted to nothing more than an annoyance. But in his new book, The Left-Hander Syndrome, Coren provides a provocative overview chat may well keep his phone ringing. Coren argues that left-handers truly are different, that those differences are largely negative, and, in light of all the incriminating evidence that has recently come out, that it is now reasonable to conclude that left-handers are marked at birth by a deviation that is, in essence, pathological.
Coren, a right-hander, clearly realizes that this diagnosis is going to sound harsh to a lot of people, and he does what he can to soften the blow. “Before the left-handers reading this go into a panic,” he writes at one point, “please remember that pathologies come in all degrees of severity. If you have a cavity in a tooth or if you have athlete’s feet or are near-sighted, you are suffering from a pathological condition.” Coren also goes out of his way to put a human face on his subject matter. He tells us about his left-handed son, Ben, whom he doesn’t consider to be a basket case. And then there’s his left-handed younger cousin, Steve, who was unfairly chastised at a family gathering for accidentally spilling hot soup over himself and the author back when they were both kids. Contrary to the stereotype, lefties aren’t any more maladroit than the rest of us, Coren insists. It’s just that much of the world is exclusively designed with the right-hander in mind.
Still, this hardly compensates for all the negative findings that Coren cites—findings that, in terms of both breadth and depth, seem to make a much stronger case for biological determinism than anything that Arthur Jensen ever came up with. (Jensen, as may be recalled, was the University of California at Berkeley professor who began to attract attention to himself in the late 1960s by pointing to the socialpolicy implications of a troublesome statistical finding—that black children as a group scored fifteen points lower than white children as a group on IQ tests.) However, by focusing on a minority group that does not fall within any socioeconomic, gender, or racial boundary, Coren, perhaps without meaning to, provides ammunition to those who would discriminate on the basis of biology.
IT WAS TO foster more highly developed human beings that the great eighteenth-century philosopher Jean Jacques Rousseau extolled the virtues of ambidexterity. “The only habit the child should be allowed to contract is that of having no habits.”Rousseau wrote in Emile. “Let him be carried on either arm, let him be accustomed to offer either hand, to use one or the other indifferently.” But Rousseau, like his contemporaries, labored Linder the misconception that handedness is a function of learning. It is not. Rather, it is a function of how the brain is wired. And whereas children can be trained to use one hand rather than another, what can be accomplished is only a superficial transformation, because neurologically speaking, nothing changes.
Man, as it turns out, is a hopelessly lopsided animal. Moreover, he is unique in his right-handed bias. Other animals, as far as we can tell, are evenly divided within their species between righties and lefties—to the extent that they show any preference at all. The fundamental question, then, is whether for human beings left-handedness represents a normal variation—like red hair or green eyes—or a deviation, like webbed feet.
Psychologists have raised the question since as far back as the turn of the century, but in the early 1970s researchers showed a renewed interest after a Canadian neuropsychologist named Paul Bakan, at Simon Fraser University, published a series of short, controversial articles arguing that all left-handedness can be thought of as a manifestation of some prenatal insult to the central nervous system. In the early 1980s Stanley Coren and his research team followed up with a series of studies in which mothers were surveyed on their pregnancies. Striking correlations were found between lefthandedness and such birth complications as RH incompatibility, prolonged labor, and breathing difficulty. Further evidence of a link came in 1987, when the Lancet published a study showing that among babies of extremely low birth weight, 54 percent are left-handed—about five times the frequency of left-handedness in the general population. In yet another study conducted by Coren—this one published in The New England Journal of Medicine in 1990—women over forty were found to be 128 percent more likely to give birth to left-handed children than women in their early twenties.
These statistics provide a pretty good basis from which to argue that some left-handedness is related to prenatal injury. Moreover, the argument makes sense neurologically: we know that the brain’s left hemisphere (the dominant hemisphere in right-handed people) is more vulnerable to prenatal injury than the right hemisphere, and so it is entireh plausible that birth complications will result in a dominance shift—that is, left-handedness. But as reasonable as this argument might sound, does it prove conclusively that all left-handedness is pathological? To his credit, Coren does not approach the question dogmatically. Instead, he behaves like a detective on a case with numerous twists and turns. And sometimes, he admits, the clues don’t add up. For example, Coren considers whether or not there is a genetic component to lefthandedness. At the outset of his research he suspected there was. But then it was determined that only 76 percent of all identical twins have the same handedness, which is virtually the frequency that would be found it completely unrelated individuals were paired off—strong evidence that lefthandedness is not genetic, since identical twins have exactly the same genes. However, if both parents are left-handed, the chances of their having a lefthanded child are up to four times as great as if neither parent is left-handed. This suggests that there is some geneticconnection. But if the connection were a straightforward one, the odds would be even greater. “If you believe that left-handedness is genetically determined,” Coren confides, “this kind of data is enough to give you a headache.”
The most compelling mystery of all, though, is why there are so few older left-handers. Coren became curious in the early 1980s, after he compiled a data base of more than 5,000 people. As a function of age, the distribution he found was most striking. Fifteen percent of the ten-year-olds in his sample were left-handed, yet among fifty-yearolds the frequency was only five percent, and among those eighty or older less than one percent. Where did all the left-handers go? One hypothesis is that left-handers gradually assimilate by learning how to be right-handed. But changing one’s orientation can be very difficult, even under coercion, and past early childhood the chances of pulling it off are dramatically reduced. Thus the gradual-assimilation hypothesis doesn’t appear to hold up. And so one has to face the grimmest of possibilities: that older left-handers aren’t being found because they are not there to find.
This is where Coren and Halpern’s baseball study comes in. When the results were published, a number of objections were raised. One particularly outspoken critic was a left-handed number cruncher with the Canadian Statistical Analysis Service named Max Anderson. Anderson even went so far as to recalculate the data, and found that left-handers born after 1890 actually outlived their non-lefty contemporaries. Coren countered that Anderson had not done as good a job of excluding ambidextrous players as he had. But no matter. Even before the critics had a chance to respond, the researchers were well into another study.
This time Coren and Halpern obtained more than 2,500 fresh death certificates from two southern-California counties, and then contacted next of kin to determine the orientation of each deceased person. Their findings, which were published last April in The New England Journal of Medicine, were startling: Women right-handers, on average, outlived left-handers by almost five years. And right-handed men experienced an extraordinary ten-year advantage. If the analysis can be believed, this means that left-handedness correlates to a bigger difference in life expectancy than smoking two packs of cigarettes a day.
DOES ANY of the new research reflect anything positive about being left-handed? Pickings seem slim, but Coren does find a few good things to say. For one thing, lefthanders appear to be overrepresented in art and architecture schools as well as in prisons and in groups of delinquent children. (Leonardo da Vinci, Raphael, Hans Holbein, and Pablo Picasso were all left-handed.) This conforms with the view that the brain’s right hemisphere (the dominant hemisphere in left-handers) is better equipped to think in spatial terms. Moreover, while they are overrepresented among the mentally retarded and other intellectually impaired groups, left-handers also show up in above-average numbers among children with extremely precocious mathematical abilities.
Finally, by citing aspects of the world that are designed for right-handers— from power tools to kitchen knives— Coren is able to present his left-handed readers with a cause and hence leave them with a potential sense of empowerment. Lefties are six times as likely to die of accident-related injuries as righties, he points out—a discrepancy that could go a long way toward explaining the life-expectancy gap. Thus, Coren argues, left-handers should organize and mobilize (even to the point of militancy) to make the world safer for themselves.
It’s a curious call to arms, perhaps, from a man who labels left-handedness pathological, but then The Left-Hander Syndrome poses a question that is not easily resolved: What happens when modern science manages to confirm old and supposedly outdated prejudices? Coren’s research leads him to conclude that for a significant number of lefthanders, the condition results from an injury to the brain, and that while lefthandedness itself is a harmless trait, it is a marker for other things that can go wrong. In the Middle Ages such information would have been seized upon as confirmation of the view that lefthandedness was evil. Now we must decide: If Coren is right, and left-handers are indeed biologically more fragile, should prospective employers and insurers be allowed to inquire about handedness? Should handedness be weighed as a factor in determining whether a candidate is fit for office? Coren refrains from draw ing any policy implications from his research that go beyond raising safety for lefties to the national agenda. Clearly his heart is in the right place. But because Coren presents as compelling a connection as he does between fare and a single physical trait, his work could easily be used by some to justify discrimination. What society doesn’t need, though, is another minority group to beat up on.