The Background Hum.(Ian McEwan's novels)

All novelists are scholars of human behavior, but Ian McEwan pursues the matter with more scientific rigor than the job strictly requires. On a recent hike through the woods surrounding his new country house--a renovated seventeenth-century brick-and-flint cottage, in Buckinghamshire--he regularly punctuated his observations about Homo sapiens with the citation of a peer-reviewed experiment. After discussing his many duplicitous characters--such as Briony Tallis, the precocious adolescent of his 2001 novel, "Atonement," who ruins two lives when she makes a false accusation of rape--McEwan pointed to a "study in cognitive psychology" suggesting that "the best way to deceive someone is first to deceive yourself," because you're more convincing when you're sincere. ("She trapped herself, she marched into the labyrinth of her own construction," McEwan writes of Briony. "Her doubts could be neutralized only by plunging in deeper.") Speaking of the way that the brain surgeon Henry Perowne, of his 2005 novel, "Saturday," struggles with the impulse to take revenge on a man who invades his home, McEwan made reference to brain scanners: "When people take revenge, the same reward centers of the brain are activated that are associated with satisfying hunger, thirst, sexual appetite. It was rather bleak, the perception."

Writers have long been content to generate such insights on their own--somebody without the aid of a brain scanner came up with "revenge is sweet"--but McEwan is wary of relying too much on intuition. He has what he calls an "Augustan spirit," one nourished equally by the poems of Philip Larkin and by the papers in Nature. Indeed, he told me that his 1997 novel, "Enduring Love," in which a relentlessly rational man defeats a relentlessly irrational stalker, was conceived as a reply to the "unexamined Romantic assumption that still lingers in the contemporary novel, which is that intuition is good and reason bad."

McEwan's interest in science isn't antiseptic; it sets his mind at play. He is surely the only novelist who owns a tie patterned with images of a craniotome--a tool for drilling holes in the skull. When he spots an opportunity, he will conduct an amateur experiment. After he wrote the Nabokovian coda to "Enduring Love"--a pastiche of an academic case study of Jed Parry, the stalker--he mailed it to one of his best friends, Ray Dolan, who directs the Wellcome Trust Centre for Neuroimaging, in London. "The package appeared to be from a psychiatrist in Dublin," Dolan recalls. "It said, 'I just had this article published in the British Journal of Psychiatry.' It was formatted just like pieces in the journal, with two columns and a header. I sat down that evening to read it. I was halfway through before the penny dropped." Three years ago, McEwan culled the fiction library of his London town house, in Fitzroy Square. He and his younger son, Greg, handed out thirty novels in a nearby park. In an essay for the Guardian, McEwan reported that "every young woman we approached . . . was eager and grateful to take a book," whereas the men "could not be persuaded. 'Nah, nah. Not for me. Thanks, mate, but no.' " The researcher's conclusion: "When women stop reading, the novel will be dead."

McEwan's empirical temperament distinguishes him from his friends Martin Amis, Salman Rushdie, and Julian Barnes. McEwan recalls a recent afternoon spent with Barnes: "Julian was reading an article in the Guardian about a ship that, in 1893, got frozen in the polar ice. The explorers had set up a primitive wind turbine for electricity, and the captain's log described how they'd got it running just before the final sunset that marked the beginning of the dark Arctic winter. Julian handed the story to me. I read it and said, 'That's amazing. A wind turbine in 1893!' He said, 'No, no, I mean the captain's description of the final sunset. What a beautiful piece of prose.' And I said, 'Oh. Yeah, yeah.' "

Perhaps the one thing that McEwan shares with his more Romantic peers is a love of the long walk. At sixty, he has probably rambled more miles than any English writer since Coleridge. For four decades, he has canvassed the Lake District and the Chilterns--the chalk hills between London and Oxford. Outside England, McEwan has conquered swaths of the Bernese Oberland, the Atlas Mountains, and the Dolomites. Usually, he walks slightly ahead of a companion, and his knapsack contains two stainless-steel cups and a very good bottle of wine. McEwan's journeys have grown even more exotic since the international success of "Atonement," which has sold more than four million copies since it was published. In the winter of 2007, after McEwan completed publicity rounds for the novella "On Chesil Beach" and the film of "Atonement," he and his wife, Annalena McAfee, a former editor at the Guardian, travelled for three months; they trekked the Himalayas, the Southern Alps of New Zealand, and the coast of Tasmania.

Our hike, on a breezy summer day, began in a sloping field of wildflowers behind McEwan's cottage. He had worked hard to create the pastel plot, now waist high. "A wildflower meadow is a matter of incredible artifice," he confessed at one point. "It's hard for flowers to defeat grass. I had a local farmer help me." A German gardener assists in maintaining the grounds.

McEwan was spending much of the summer in Buckinghamshire, trying to settle into a new novel. He said that "On Chesil Beach," which is about an English couple's disastrous wedding night, in 1962, had "struck a nerve in France," and interviewers were pursuing him in London again. At a moment when the hardback novel seems endangered, McEwan's work is almost scandalously popular. Although his novels headily explore ideas, and his gift for visual detail approaches that of John Updike (Briony's cousin, fondling a suitcase: "The polished metal was cool, and her touch left little patches of shrinking condensation"), his international success has a lot to do with an old-fashioned talent for creating suspense. His plots defy what he calls the "dead hand of modernism." (Even "Saturday," which takes place in a single day, has enough incident to rival "24": a plummeting plane, a car crash, a break-in, a tumble downstairs, lifesaving surgery.) McEwan said that one of his goals was to "incite a naked hunger in readers." He discussed his technique reluctantly, as if he were a chemist guarding a newly filed patent. "Narrative tension is primarily about withholding information," he said.