In The Sense of Style, Steven Pinker develops the theme of the reader’s experience, pointing to numerous studies that reveal how readers take in new information and make meaning and memories from what they have read. Pinker explores how reading requires different kinds of mental effort, advising writers to embrace strategies that minimize the effort to understand their prose, so the reader can more easily understand their ideas.

With every word, the writer makes “cognitive demands” on a reader:

As the reader works through a sentence, plucking off a word at a time, she is not just threading it onto a mental string of beads. She is also growing branches of a tree upward. […] So every time a writer adds a word to a sentence, he is imposing not one but two cognitive demands on the reader: understanding the word, and fitting it into the tree (104).

Pinker notes that this scientific insight supports the traditional advice to writers to “[o]mit needless words,” since superfluous words further burden readers without providing any additional meaning (104).

Pinker points to mental effort to explain other conventions. He observes that confusing negations require readers to attach a “mental tag” to false statements in an effort to remember them.