Image Mr. Weir’s neighborhood Credit... Sasha Maslov for The New York Times

The place is steps from what Mr. Weir describes, only half tongue in cheek, as the “groovy dad Gowanus coffee shop,” a.k.a. the brick-walled Root Hill Cafe on Fourth Avenue. “It’s always filled with lots of arty, paint-spattered stay-at-home dads,” Mr. Weir said, “along with kids wearing natural fabrics.” He suspects that everyone he sees hunched over a laptop is laboring over a webcast TV show.

An incident that occurred his first week in the neighborhood encapsulates what he likes about it. Mr. Weir needed a slab of plywood for his bed. He poked his head into an artists’ supply store, where a blue-jeaned worker “gave me a piece of wood and said, ‘O.K., man, just take it for free and pay it forward.’ It was like something out of a movie.”

“I’m still a little afraid of how groovy and arty my neighbors are,” said Mr. Weir, who is working on a novel about a 50-something man much like himself living in a neighborhood much like Gowanus. “To be honest, I don’t feel hip enough for Brooklyn. But when you’re 55, and you see people forming themselves and determining what they’re going to be, that’s a good feeling. I like being around people who haven’t fully found themselves.”

A variety of forces are drawing people in their 50s and 60s to neighborhoods that until recently were better known for crime than cool.

“Low crime is God’s gift to gentrification,” said Harvey Molotch, a professor of metropolitan studies and sociology at New York University. “The decline of violent crime in the city, especially random crime — the stray bullet — has significantly opened up the so-called frontier. The need of the fearful to cluster in a fortress, in a secure zone like the Upper East Side or later, Park Slope, is alleviated. People have more choice, and they can feel comfortable venturing farther from home base.”

Sometimes the attractions are more subtle.

“Some of these people previously lived in neighborhoods like the Upper East Side, the Upper West Side or Park Slope, and now that the kids are out of the house, they want to resume their pre-parent lives, to pick up where they left off,” said Sharon Zukin, the author of “Naked City: The Death and Life of Authentic Urban Spaces” (Oxford University Press, 2009), a study of the evolution of onetime fringe neighborhoods like Williamsburg and the East Village.