Gail Sheehy, the journalist and author whose Passages became one of the most enduring books of the 1970s, has died of pneumonia at 83, the New York Times reports.

Sheehy was a pioneering writer in the genre of creative nonfiction and was known for her abiding interest in human behavior, which informed many of the more than a dozen books she published during a long career.

Sheehy began her career in writing as a journalist, first for newspapers and then for New York magazine. Her first book, a novel called Lovesounds, was published in 1970; she followed that up with a nonfiction book, Panthermania:The Clash of Black Against Black in One American City, the following year.

In 1976, she published Passages, about the “predictable crises of adult life.” The book was a huge hit, and stayed on the New York Times bestseller list for three years.

It also inspired many of her other books, including The Silent Passage, about menopause, New Passages, and Understanding Men’s Passages.

Her most recent book, Daring: My Passages: A Memoir, was published in 2014. “Daring, the author amply shows in this spirited life story, defines her,” wrote a reviewer for Kirkus, calling Sheehy an “audacious pathfinder.”

In an interview with NPR about Daring, Sheehy said she “wasn't writing about the nice, long, calm periods” of her life.

“In my memoir I admit that I’ve been as fearful of success as of failure,” she said. “In fact, when Passages was published, I so dreaded bad reviews that I ran away to Italy with a girlfriend and our children to hide out.”

Michael Schaub is a Texas-based journalist and regular contributor to NPR.