Writing guides tend to be pretty unsatisfying. They offer plenty of concrete rules, but why, a reader might ask, should the rules be followed? The answer is usually “because” — as in, “because I say so.” This, of course, is where humanity found itself before the advent of the scientific method: the mystics spoke, and everyone had to decide for themselves whom to believe. Harvard psychologist Steven Pinker takes a different approach, one that is both more ambitious and more modest. In his new book, “The Sense of Style,” he draws on research, and particularly his deep knowledge of linguistics, to give his writing principles a scientific basis. Readers can thus have some assurance that Pinker’s advice is good, and, knowing the reasons why, they will be more likely to know when a rule should be broken. Yet he does not push this method beyond its natural limits. Scientists, after all, still know relatively little about the ways dark squiggles communicate ideas. Instead, he shows readers how to take apart a piece of fine writing to see what makes it tick. He does this with affection and enthusiasm. In Pinker’s hands, we do not feel ordered around capriciously, but truly guided by an inspiring teacher. He was interviewed by Gareth Cook, the editor of Mind Matters.

There are many, many books about writing in the world. What did you hope to add?
Most writing guides recycle a standard set of peeves and superstitions about usage, mixed with useful but vague guidelines like “keep related words together.” None of them take advantage of the tremendous advances in the study of language of the past fifty years — modern grammatical theories that are a vast improvement over the old Latin-based grammars; evidence-based dictionaries which pay attention to how language really is used; research from cognitive science on what makes sentences easy or hard to read; and historical and critical studies of usage, which trace the history of various rules (like the one against ending a sentence with a preposition) so that their rationale can be examined. I wanted to write a style manual for the 21st century.

That’s fascinating. Can you give any examples of writing lessons that come from cognitive science research?
A student press release at Yale advertised “a panel on sex with four professors,” which sounded much racier than it was. These ambiguities are common in careless prose. Usually the unintended meaning is not humorous, just distracting, and often the ambiguity is resolvable a few words downstream, like one that I came across the other day: “John Kerry arrived in Baghdad on Wednesday to endorse the new Iraqi government hours before President Barack Obama will address the American people about his strategy for combating ISIS militants”—it sounded for a second as if he was endorsing government hours (were they now working 9-5?). Text that has a lot of local ambiguities is frustrating to read, because it constantly forces the reader to backtrack and reinterpret. One of the things that differentiates “smooth” from “choppy” prose is the absence of these dead ends.

The authors of traditional style guides, like Strunk and White, were dimly aware of the problem, but lacked the technical concepts to analyze it, and offered useless advice such as “Keep related words together.” The advice is useless for the Yale sentence, the related words panel and on sex in fact are already together; disambiguating it requires moving related words apart to get a panel with four professors on sex. For that matter, if it had been a panel on drugs with four professors, then the word-moving solution would make things worse: a panel with four professors on drugs is just as misleading as the panel on sex with four professors.

Psycholinguists call these temporary ambiguities “garden paths,” and have run hundreds of experiments on what causes them and what prevents them. In the Yale example, the problem is that the human sentence understanding process parses sentences with the help of statistically frequent word pairs that have a standard structure and meaning—in this case, sex with X,and X on drugs. A careful writer has to scan for them and recast the sentence to avoid the ambiguity. The advice is better stated as “pull unrelated (but mutually attracted) phrases apart.”

It seems that it is pretty standard, in books about writing style, to bemoan the decline of the written word. Yet you don’t. Why?
Every generation thinks that “the kids today” are ruining the language. They confuse changes in themselves (people pay more attention to language as they get older and consume more text) with changes in the times. Studies of writing quality in student papers have shown that there has been no deterioration over the decades, and no, today’s college students don’t substitute smiley-faces and texting abbreviations for words and phrases.

You write of “directing the gaze of the reader to something in the world she can see for herself.” Can you explain what you mean by this and how it defines your view of good writing?
The main difference between good writing and turgid mush—academese, corporatese, and so on—is that good writing is a window onto the world. The writer narrates an ongoing series of events which the reader can see for himself, if only he is given an unobstructed view. In academese, the writer’s chief goal is to defend himself against the accusation that he is naïve about his own enterprise. So academics describe what other academics do instead of what they study (“In recent years there has been increased interest in X”). They use many metaconcepts—concepts about concepts, likelevel, perspective, framework, and approach—instead of writing “call the police,” they write, “approach this problem from a law-enforcement perspective.” They turn verbs into nouns—instead of writing, “People cooperated more,” they write, “Levels of cooperation increased.” And they sprinkle their prose with hedges—somewhat, virtually, partially—in an attempt to get off the hook should anyone ever try to prove them wrong. +

Did working on this book change how you approach your own writing in any ways?
Yes. It made me more aware of the coherence connectors — like “but,” “so,” “after,” “moreover,” and “nonetheless” — which play such an important role in weaving sentences into a coherent argument. And it made me even more dependent on modern dictionaries, which don’t just prescribe correct usage, but in their usage notes, comment insightfully on the history and range of variation in the use of a word or expression.

I really enjoyed the way the book examines examples of good writing, and then explains what makes them good. Why did you decide to do that?
When I asked some good writers which style manuals they read when they were starting out, the most common answer I got was “none.” Good writers acquire their craft not from memorizing rules but from reading a lot, savoring and reverse-engineering good prose, and assimilating vast numbers of words, idioms, tropes, and stylistic habits and tricks. On top of that, my earlier research on irregularity reminded me how much in language is arbitrary and illogical and must be acquired not by logic or rule but by brute-force memorization—spelling and punctuation being prime examples. I wanted to emphasize how important careful reading is to good writing, so I began by letting readers eavesdrop on my stream of consciousness as I went over a few examples of prose that pleased me and tried to become conscious of what made it so good. That’s a key to becoming a good writer.