You, too, have an optimal sentence length

Plain-writing proponents advise you to check your documents’ average sentence lengths to guarantee against excess: Bryan Garner recommends an average of 20 words per sentence, and some plain writers recommend 15. Since every writer has an optimal average sentence length, the better advice is to use your own optimum rather than an arbitrary standard. I find, in fact, that when the average sentence length departs from my average, the document needs more work. Nobody has previously explained why writers consistently prefer a certain average sentence length, but inasmuch as “writer’s voice” is mostly sentence length, an explanation could help writers find their “true voice.”

I assume excellent writers prefer their strengths to their weaknesses, and I hypothesize that optimal sentence length is a trade-off between two abilities integral to writing: abstraction and sequencing. Typically, we construct sentences by abstraction and paragraphs by sequencing. Constructing a coherent sentence requires abstracting a suitably deep idea, but linking sentences to form cohesive paragraphs requires attending to their sequential relations. Long sentences capitalize on the writer’s ability to entertain a complex abstraction to be stated in words. Short sentences capitalize on the writer’s ability to link ideas in successive sentences. To make the most of their ability to entertain complex abstractions, writers strong on abstraction compared to sequencing will write long sentences, and to make the most of their ability to sequence thought, writers strong on sequencing compared to abstraction will write short sentences.

The distinction between abstraction and sequencing sounds somewhat like right and left hemisphere, but it isn’t. Here, we’re not talking about whether the internal processing is simultaneous or serial but whether the output is a unified abstraction or a sequence. The dimension of relative strength in abstraction compared to sequencing most resembles construal level: abstraction being far (resulting from abstract construal) and sequencing near (resulting from concrete construal). Personal consistencies in tendency to think far or near are shown, as in the finding that people who wake up late and prefer to work at night (“night owls”) tend to think far.

One educator’s questionnaire estimates your position on what amounts to far versus near thinking, conceived as Global-versus-Sequential learning style. (Hat tip: Words, Ideas, and Things.) I’d be interested in anyone’s results measuring their sentence lengths and testing their Global-Sequential position. My average sentence length is 25 and Global-Sequential learning-style score is 7 (moderately high Global). 

If you apply this test, bear in mind these caveats: 

1. Short documents will diverge from your average due to random statistical fluctuation.

2. Some documents should diverge from your optimum when the need to write in a particular voice outweighs achieving your highest literary quality.

3. Any document will not only be more interesting but also clearer if you vary the sentences' length. 

The writer's ineffable "voice": The immutability of optimal sentence length

When a friend phones, you know her identity by the sound of her voice. This is the basis for the writer's-voice metaphor, but it’s only a metaphor. The features distinguishing spoken voices refer to the physical dimensions of the sound waves the vocal chords produce, and a pen’s scratch or a keyboard’s click are failed candidates for the voice that’s purported to infuse the scratcher or clicker’s document.

If the spoken voice is the usual metaphor, expression of the writer’s personality is the standard explanation, although it retreats to a murkier metaphor. A real explanation would link the specific characteristics of writing said to constitute voice to specific personality traits. Perhaps someone will someday link writers’ personality traits to expressive style, but before theorists can even speak of a linkage between personality and manner of written expression, they have to know the expressive traits voice comprises. When graphologists, for example, claim styles of handwriting are linked to the writers’ personalities, they have in mind connections like, “If the writer makes her dots above her letter ‘i’ like little circles, she will have histrionic tendencies"; or, “A rising baseline expresses an optimistic outlook.” Writing-voice exponents don’t specify any candidates for the expressive equivalents of circular dots or upward slope, never mind whether they correlate with personality.

Nobody knows how to talk about writers’ voice; yet, some writers manifest a distinct “voice.” Why should being specific about what they manifest be so difficult? My answer is that there’s an obvious solution, but it is, on second thought, obviously wrong—so obviously, that we don’t even consider it; but no other solutions are forthcoming. The obvious solution is that expert writers whose voices are said to differ write sentences distinctive in their length. The rebuttal is that, if voice is worth discussing—if writers can find their authentic voices—then voice can’t be a trait writers adopt as casually as making their sentences longer or shorter. Finally, the mistake the rebuttal commits is ignoring that an expert writer lacks the capacity to change his average sentence length without damaging his expressive capability: optimal average sentence length is immutable.

If you’re like me, when pressed for examples of distinctive voice you think of Hemingway and Faulkner, who are so unlike in the length of their sentences that it overshadows other differences. A second formal difference between them, preference for common versus esoteric words, accommodates different typical sentence lengths: to cohere, long sentences require abstraction. But problematically, average sentence length seems a matter of choice or preference, rather than an inherent personal quality. The idea that finding your voice means achieving stability at your optimal sentence length strikes, at first, as crudely reductionist. Writing teachers often advise students to shorten their sentences, and to the extent this advice helps, it would not seem tantamount to directing students to write in an inauthentic voice. Misleading in this scenario is that we’re talking about students who haven’t "found" their voices—and probably never will. Imagine telling Faulkner to shorten his sentences.

An element of commercial branding probably contributed to polarizing the Hemingway-Faulkner contrast, but I have an example of a professional writer being “told” to shorten his sentences. Science writer Steven Berlin Johnson—on whose casual research the present sentence-length theory of voice is based—found that Malcolm Gladwell’s average sentences were 6.5 words shorter than Johnson’s. His reaction is telling, Johnson declaring, “A 25% drop in sentence length has to alter the reading experience dramatically"; and he joked, “Clearly, the only things separating me from selling ten million copies of my books are those extra 6.5 words per sentence.” While this was overstatement—the writers’ topics no doubt affect their popularity—it probably isn’t entirely false, since a greater number of readers can understand short sentences than can understand long ones. This is why primary-school texts contain very short sentences! Yet, there’s no sign that Johnson—already an accessible writer—tried to make his writing still more accessible by using shorter sentences. Instead, Johnson’s posting focused on each writer's invariant sentence length—evidence that, for the expert writer, optimal sentence length is an immutable trait. For immature writers, the advice to shorten sentences nudges them toward their “authentic voice” or, at least, toward a degree of syntactic complexity they can manage, but it can be taken too far—and often is.

Expert-writers' consistency in their works' syntactic complexity is evidence that mature voice is optimal average sentence length; evidence against this hypothesis is that average sentence length has declined over the years, from 50 words in pre-Elizabethan times, to 29 in Victorian times, to 20 words per sentence, today. (William H. DuBay. (2006) Unlocking Language: The Classic Readability Studies.) If optimal average sentence length is voice, it shouldn't change over generations: if environments change it, then why not training regimens, so that Steven Berlin Johnson could train himself to write shorter sentences—to write more like Malcolm Gladwell?

The objection seems surmountable. In an era when a “good writer” was expected to average more than 30 words per sentence, one who could sustain only 20 would choose a different occupation; today, it can seem the reverse is true. With popular writing style ever increasingly that of marketers, it may seem that those whose genes cause them to write their best using complex syntax will be declared incompetent. But this is unlikely: the unity of language and thought suggests that well-managed syntactic complexity accompanies competent ideational complexity. Before mass advertising arose, the world might have found little use for the master of the simple sentence, but today's complex world still needs complex thinkers.

Unique style: expressive or substantive

Often in discussions about writing excellence, the point is made that the best writers have a unique style. Little is said to describe the contours of this style. Style has been the subject of previous entries, which define styles as tradeoff patterns among writing Virtues, but the unique styles don't mean tradeoffs skilled writers purposefully modify. "Unique style" refers to something else, but what?

Some treatments, sporting a touch of New Ageism, call this unique style the writer's "voice." These authors promptly add that voice identifies a writer like fingerprints identify ordinary persons. So is it like a voice or like a fingerprint? They're not the same. Only a universal truth about fingerprints, the absolute uniqueness of each, lends them the least interest to most of us. We usually don't even bother to form an opinion about whether one's fingerprint is attractive, more-than-usually unique, or in other manner worthy. Not so with voice. While no aspirant lands a job because of the aesthetics of his fingerprint, the aural media demand vocal qualities, innate and trained. Some voices are more attractive than others, and their attractiveness is independent of the utterance's content, the assessment part objective, part subjective.

Is a writer's unique style a voice or a fingerprint? Surely if this unique style exists, it resembles voice. Unlike a fingerprint, it obtrudes itself; we can't avoid the writer's style. If in contradiction, unique style turns out to be some subtle, technical variance, then we may avoid noticing it — hardly surprising, as it becomes irrelevant. Rather than being like voice, style would have the uniqueness of handwriting in a future civilization where none use this skill.

To the contrary, style obviously matters, yet seems impossible to define in a way keeping the supposed unique and involuntary character. Unique style is supposed to be an expressive quality that becomes more pronounced as the writer skilled. If unique writing style existed, the best writers would suffer scorn for freakishness, not only win acclaim for uniqueness. Any distinctive "voice" can annoy, will annoy someone. Yet, we find no literary critics who simply despise Shakespeare. Shakespeare's distinctiveness, we can conclude, doesn't derive from a unique writing style.

Opposed to these expressive accounts of unique style, an author's unique "style" should be conceived as intellectual style, not anything inhering in sentence or paragraph composition. Writers come to identify their intellectual strengths and learn to exploit them. When a writer settles on a style, he adopts a set of approaches to intellectual (or literary) problems.

Writing Styles

Once, two professional writing styles, the Attic and the Asiatic, vied for dominance.

"From classical Greek and Roman times, two literary traditions have grown alongside each other. One, a florid oratorical style called Asiatic prose, sported elaborate antitheses, complicated syntax, and correspondences in sense and sound. The other, Attic prose, was refined conversation: concise, restrained, shorn of intricacy." (Garner, The Elements of Legal Style (1991) p. 7.)

Today, it is said only the Attic remains standing, but Attic and Asiatic are really but points on a continuum; while the Asiatic extreme has died, and the Attic survives in the "plain English" school, all that is not Attic is not Asiatic, and your ghostwriter should be fluent in a spectrum of styles. Different weights on the writing virtues, Concision, Clarity, and Euphony, define the Attic and Asiatic styles, although both styles work within the constraint that Concision is the pre-eminent writing virtue. Within that constraint, the Asiatic gives still greater weight to concision, and the Attic gives negligible weight to Euphony.

That the Attic style emphasizes Clarity surprises no one, but claiming the Asiatic hyper-emphasizes Concision is unconventional. The prolixity of the Asiatic style is only apparent, however, the tightly worded but complex prose attaining heights of information compression. Appropriate even in its heyday only when conveying dense information, the Asiatic style was never the tool of choice for drafting a short business memo. Justice Cardozo — a master of the Asiatic style, Attic style, and the shades between — explained that the Asiatic style is suitable to cases hinging on a nuanced probate instrument's interpretation.

Apart from the writer's spontaneous adaptation of style to material, semi-Asiatic styles serve purposes in brief writing. The style of writing is one of the few ways, for example, to appeal directly to the judge's emotions. When writing to a hostile court, the writer should use more Euphony, to create positive feelings that can become conditioned to your position and help improve the judge's opinion of it, and more Concision, to avoid above all trying the judge's patience.

To see a shift from a more Attic to a more Asiatic writing style, compare briefs I wrote to the California Supreme Court before and after I learned of the court's hostility.