BEING LEFT-HANDED is nothing special, as much as left-handers (of which I'm one) might like to believe otherwise. Handedness itself — the fact that most people favor one of their hands, detracting from the symmetry between the left and right sides of the body — is intriguing; so is the fact that left-handers make up only roughly 10 percent of the population around the globe. But the actual experience of being left-handed is rather mundane, by most accounts. In the United States, in the not too distant past, it went something like this: When you were young, you struggled to operate your classmates' scissors. The paper bunched up awkwardly and made finishing an arts and crafts project take a few minutes longer. You completed an assignment with ink smudges down the length of your pinky finger. Maybe you picked up a guitar and had to hesitate with the fingering for a few moments. When you were older, you bumped elbows with a right-hander at a restaurant if you didn't seat yourself strategically. You had to rearrange the knife and fork — or maybe you couldn't, for reasons of etiquette. These are the stories that lefties remember; these are the anecdotes that get revisited, for polite chuckles, at cocktail parties.
These days, even these minor differences may be disappearing. In 2011, schoolchildren spend more time typing than they do writing, and etiquette is being phased out. And so, a few moments of discomfort notwithstanding, life plays out pretty smoothly for today's left-handers. You are classified as a lefty only insofar as you choose to be (or insofar as you choose to play sports, where left-handedness can be a definite advantage). To be left-handed is to belong to a club by accident, a club with a single, clear identifying feature that nevertheless gives no real sense of identity to the club. If you want left-handedness to mean more, you have to make it mean more. You have to go around wearing T-shirts that say things like, "If the left side of your brain controls the right side of your body, and the right side of your brain controls the left side of your body, then left-handed people must be the only ones in their right minds" (attributed to southpaw comedian W.C. Fields). You have to subscribe to the image of lefties as savants. You have to exclaim, "Benjamin Franklin was a lefty, and so was M.C. Escher. So were five of the last seven U.S. presidents. And so am I!" Most lefties do a roll call of illustrious left-handers from time to time (Caesar! Michelangelo! Hendrix!). It provides us with some inspiration on our off-days.
Yet just as left-handers can sometimes be inclined to make too much of their distinguishing mark, so is there occasional misplaced excitement for the phenomenon in the literary world. Rik Smits's The Puzzle of Left-handedness is the latest attempt to provide a survey of how lefties have been portrayed, conceived of, and accounted for through the centuries, and although Smits casts a wide net and writes with evident enthusiasm, it isn't clear, by the end of the book, why he took the trouble to write it.
There are interesting moments littered throughout, to be sure. If nothing else, Smits's sketch-like chapters show that left-handedness can be used as a lens through which to examine larger historical trends. In ancient times, and up to the medieval ages, when superstition stood in place of explanation, left-handedness had moral connotations. It was associated with an inversion of the natural order. Paintings depict God as good and truthful and right-handed, and the devil, God's evil and dishonest opposite, as left-handed. During the Renaissance, the notion of inversion took on a pseudoscientific air. The Italian commentator Lodovico Richeri hypothesized that all left-handers were afflicted with situs inversus, a condition in which the internal organs are reversed. (As it happens, situs inversus does exist, but it occurs in only 0.01 percent of the population, far too little to be the cause of left-handedness.) This belief persisted until the early part of the 19th century, when the assumptions of popular psychology seeped into scientific explanations of left-handedness. According to one analyst, Abram Blau, it was "'nothing more than an expression of infantile negativism,'" a rejection of the norm of right-handedness, "comparable to 'contrariety in feeding and elimination, retardation in speech, and general perverseness insofar as the infant with meagre outlets can express it.'"
More recently, psychologists and neurologists have tried to find a biological basis for left-handedness. One theory, proposed by Marian Annett in the 1970s, held that handedness could be explained by a notion of dominant and recessive traits, much in the way that brown and blue eyes are. Right-handedness, like brown eyes, would be a dominant trait. The twist: Left-handedness was not the recessive trait. Rather, the recessive trait was a genetic indifference to hand preference. If you receive one copy of the dominant allele from your parents, you'll turn out to be right-handed, but if you receive two copies of the recessive allele, then it becomes a toss up between left-handedness and right-handedness.
Another popular theory, put forward by the behavioral neurologist Norman Geschwind around the same time that Annett was doing her work, pointed to hormones. Geschwind claimed that people who were exposed to high concentrations of testosterone as fetuses were more likely to be left-handed. Excessive testosterone exposure correlated well with slightly higher incidences of dyslexia and epilepsy, and so, Geschwind noticed, did left-handedness.
The trouble with both these theories, says Smits, is that they fail to account adequately for the surprising connections between left-handedness and twins. Not only is left-handedness twice as common among twins as among regular siblings, but left-handers are twice as likely as right-handers to produce twins. This eerie link lies at the heart of another modern theory (and Smits's favorite): that "being a monozygotic twin is a precondition of being left-handed." In other words, only someone who has had a twin in utero can be truly left-handed. The twins are mirror images of one another; one is left-handed, and the other right-handed. Of course, left-handedness doesn't require that one ultimately be born with a twin. If only one fetus results at the end of term, that means the other died in the womb and was absorbed by the mother: a "vanishing twin."
There are two major problems with this theory, as Smits notes. One is that many twins vanish so early in a pregnancy that they are never detected. Without knowing how frequently they occur, nobody can be sure whether twins account for the 10 percent occurrence of left-handedness in the population. Another problem — one that dogs all studies about left-handedness — is that handedness is not truly a binary phenomenon: Many people use their left hands for some tasks and their right hands for others. Few are exclusively left- or right-handed.
There is no final word, then, on the causes of left-handedness. Left-handers, apart from their hand preference, seem to be distinguishable from their right-handed counterparts only in that their brains are slightly less lateralized. On the final page, Smits sums things up disappointingly: "Left-handers seem, as far as we can tell, simply to be left-handed." For a scientific work, this might be an acceptable, if weakly phrased, conclusion, an indication that, while much research has been done, there is more yet to do. But Smits's book is billed as an attempt to put left-handedness in a broader context; scientists may be content simply to be accurate, but for cultural history, the "so what?" question matters. In a broader work like Smits's, the conclusion above would be acceptable only if the set-up had enough highs and lows to justify such a null payoff.
And this is the chief problem with The Puzzle of Left-handedness: Smits cannot decide whether he wants to stick to the bold conceit he's chosen — that "the puzzle of left-handedness" is a cultural-historical conundrum worth tracing through the centuries — or admit to the essential mundanity of the phenomenon and write a more scientifically nuanced book. The struggle between these two impulses — and the odd authorial choices that result — is evident from the book's very first lines: "'My husband's left-handed too.' The young woman sounded worried. I couldn't help laughing. Here we go again." The discussion in question has to do with the idea that left-handers die an average of nine years earlier than right-handers, a claim put forward, to minor controversy, by psychologist Stanley Coren in 1992. But has Coren's work lingered on in the cultural consciousness? Is anybody still worried?
Smits plays fast and loose with methodology, too. While ruminating on the bumbling tendencies of left-handers, Smits makes mention of "the Ford scale," a measure of clumsiness named after the bumbling President Ford — and a measure that turns out to be Smits's own invention. It might be that he's merely being cheeky, with no pretense to making or assessing a serious scientific argument. That would explain other gruesome turns of phrase, the barely relevant piece of Star Trek fan fiction that occupies most of page 190, and the research method he reportedly employed to investigate how left-handedness affects certain sexual practices: "I've asked around."
It's too bad, as there are glimpses throughout The Puzzle of Left-Handedness of the book that might have been. On a few occasions, Smits mentions societies in which left-handers have faced real persecution; an in-depth examination of at least one such society would have grounded and justified the discussion. Elsewhere, he speaks at length about the differences between left-right symmetry and top-bottom symmetry, and explains how the direction in which a language is written can affect the direction in which its speakers "read" works of art. These chapters depart from the main "handedness" topic to explore general notions of left, right, and directedness; they are all the better for it.
In the book's opening pages, Smits asserts that "human beings are simply not cut out to handle nuances, since our way of thinking is based on dualism and dichotomy." This dualistic tendency, he says, causes us to create a left-right split, when in fact such a split is a poor reflection of reality. He may be right — it would have been interesting to see that idea play out — but unfortunately, Smits is a captive of the same simplifying tendency he describes.