Nearly half a century later, Anne Bernays and Justin Kaplan look a bit different from the honeymoon snapshots on the cover of their just published joint memoir, Back Then: Two Lives in 1950s New York (HarperCollins). Her tousled curls are white now; he walks with a cane; and there's no sign of a cigarette. ("I don't want to promote smoking," he says, indicating the image of him firing one up in the streets of San Gimignano, "but everyone did in those days.") Their list of accomplishments is a lot longer today than it was when she worked as managing editor of the literary magazine discovery and he was a young editor at Simon & Schuster. Bernays has published eight novels praised for their ironic wit and storytelling verve, most recently Professor Romeo. Kaplan won National Book Awards for Mr. Clemens and Mark Twain in 1967 and Walt Whitman in 1981. Together, they've produced three daughters, a few travel pieces and an engaging meditation on The Language of Names, which appeared in 1997.

Their appearances and résumés may have changed, but the lively affection that warms the pages of Back Then as they describe their whirlwind courtship in 1953 and the early years of their marriage is still evident as they discuss their new book in a HarperCollins conference room. Their conversation is an easy mutual affair, punctuated by interjections that elaborate on a spouse's point or offer supportive asides. Their current collaboration, they agree, was quite different from the last one.

"In The Language of Names, you weren't supposed to be able to tell who wrote what," says Bernays. "In this book, there are two distinct voices. He doesn't like talking about himself, and it took a lot of persuasion to get him to do this. Whereas I love talking about myself and had sold two partial memoirs to two different publishers, then paid to get them back both times because I didn't like the way either one was written. I've been thinking about a memoir for a long time, but I didn't have a good story."

The story she found and persuaded Kaplan to join her in telling was of two young native New Yorkers from very different backgrounds embarking on publishing careers, meeting and marrying, then deciding that they both wanted to write, not edit. The book closes with the couple, baby daughters in tow, departing for the "calmer precincts" of Cambridge, Mass., where they've lived ever since.

The memoir took shape as a joint project, says Bernays, because "we started missing New York more and more."

"It got stronger and stronger, as if we'd never left," her husband adds.

"And when we thought about it at this distance, that period, 1948 to 1959, seemed unique. It wasn't like the '60s or the '90s; it had its own distinct flavor."

"We wrote it before 9/11," Kaplan notes, "but we both felt that made the period we were writing about even farther away. It's a different world now."

To capture the world of their youth, the writers worked separately on first-person narratives that were then woven together in alternating chapters. "We sat down and made broad categories: work, dating—we called that 'lust'!—psychoanalysis, education, family," says Bernays. "We agreed to each write a section on those things, and then he was going to write about the West Side, and I was going to write about the East Side." Bernays, daughter of public relations pioneer Edward L. Bernays, comes from an affluent, assimilated German-Jewish family that made its home in a Fifth Avenue luxury apartment; across the park, on Central Park West, Kaplan grew up among observant orthodox Jews from Russia.

"I did a certain amount of mean teasing about that, which she took very well," Kaplan recalls.

"He told me that Russian Jews had the brains and German Jews had the money," she adds.

"Well," he corrects her quietly, "that Russian Jews were creators and German Jews were consumers."

"The hard thing was," says Bernays, returning to the subject of the manuscript's structure, "you can't really do it thematically—you could, but we also wanted to do it chronologically. It wasn't working, so we had to go back and fit it together like a puzzle."

They credit HarperCollins's Claire Wachtel for calling their attention to these technical problems. Bernays explains, "Claire took this manuscript, which we thought was dandy—"

"And finished," interjects Kaplan.

"And not once but twice wrote all over it, not telling us what to do, but pointing out the holes."

"She has a very strenuous style of editing," Kaplan elaborates, "which is not to use those little yellow flags, but to write across the face of the manuscript."

"Sometimes she went over to the back of the page," adds Bernays. "She really was inspired; she made the book a lot better by asking the right questions. And she did an incredible job of scattering our photographs in the text." Indicating Kaplan, she continues, "He didn't want photos.".

"I thought they would make the book too historical, too documentary, and not really personal. There is this feeling that the prose ought to stand on its own feet. But I came around."

Shaped by Wachtel's comments, with photographs wonderfully evocative of the period, the book that emerged paints an atmospheric picture of "a sweeter and slower New York," as Kaplan puts it. Publishing professionals will relish the vivid, affectionate portraits of Pocket Books' Herb Alexander, S&S founder Max Schuster, discovery editor Vance Bourjaily and other key figures in the era's cultural scene. It will come as no surprise to admirers of Kaplan's biographies that his chapters cast a shrewd eye on such revealing aspects of postwar society as the craze for psychoanalysis and the increasing pervasiveness of advertising. Bernays's sections are more personal; she exposes frankly but without bitterness the sexism of her own analyst (who squelched her authorial aspirations with the comment, "Do not write. It will interfere with your life as a woman") and offers decidedly intimate details about her relationships with other men before she met Kaplan. (She lost her virginity to Anatole Broyard: what could be more literary?) Their interviewer asks if it was awkward writing these passages when she knew her husband would see them.

"Not for either of us," says Kaplan.

"We were very open with each other at the time," she adds. "He knew I had a lot of boyfriends; I knew he had a lot of girlfriends. My sister-in-law was shocked by the book. She said, 'Well, you really did tell an awful lot!' But compared to someone like Kathryn Harrison [who described a sexual liaison with her father in The Kiss], this is Dick and Jane!"

"My feeling was, there's no point in kissing if you're not going to tell," says Kaplan, with a sly smile. Although his descriptions of previous affairs are more circumspect, he too is candid: "I'd never written anything in the first person, I found it just a little scary, but then it became exhilarating in its own peculiar way, as if I'd been suppressing the 'me' all these years."

Bernays also enjoyed the break from her usual genre. "Nonfiction writing takes a much more muscular thought process. I like it because it makes me feel smart, whereas when I'm writing fiction, I'm just telling a story and I don't necessarily have to be smart. The novel I'm working on right now has a narrator completely unlike me, and taking her voice is really exhilarating. But it takes place over September 11, and I'm finding it extremely difficult and upsetting to write about. I'm not sure I can do it."

"You have to be oblique about it," says her husband.

She nods. "You can't write about the thing itself, you have to write about how it affects your characters."

Kaplan, too, has gone back to work on an individual project: the story of the bitter rivalry between cousins William Waldorf Astor and John Jacob Astor IV, who competed to build such great New York hotels as the Waldorf Astoria and the St. Regis in the 1890s. "They not only set a precedent for luxury hotels but actually changed the way people lived in public—that is, people began to do things publicly rather than quietly at home."

Will they tackle another joint endeavor? "I've been trying to get him to write a mystery with me," says Bernays. "For some reason, I get less serious as I get older. I'm not going to be Virginia Woolf; I just like to be able to keep somebody reading. Do you get less serious?" she asks her husband.

"Yes, considerably," he replies.

"It's all a big joke, anyway, isn't it?" she comments.

"That's where I disagree with you," he answers, smiling affectionately.