NEW YORK >> A year ago Robert E. Elson began noticing a curious new array of beverages in the refrigerator of the condo he shares with his wife, Roni, on the Upper West Side: energy drinks and “different coffees that were totally alien,” recalled Elson. “And there were these different milks.

“I’d see almond milk and I’d go, ‘Oh, my God,’” he said.

The appearance of almond milk and its kin coincided precisely with the residency of the Elsons’ granddaughter Madeline David, who had just begun graduate work at the Climate School at Columbia University.

“She was accepted into the program, and that was the good news,” said Robert Elson, 82, a salesperson at the real estate agency Coldwell Banker Warburg. “The bad news was that her parents told us that Madeline was going to have a problem with the room and board.

“We told them, ‘Well, we’re here. We have an extra room, so why doesn’t she come stay with us?’” Elson said.

They became “grandmates” — nearly six decades apart in age.

According to a recent survey by Credit Karma, a personal finance platform, nearly one-third of Americans ages 18 to 25 live at home with their parents or other relatives. “We’re hearing more and more about adult grandchildren living with grandparents,” said Donna Butts, executive director of Generations United, a nonprofit based in Washington that promotes programs and policies that connect generations.

Once the grandchildren are older, Butts said, skipped- generation relationships are stronger because the grandchildren and grandparents can approach each other as individuals. Grandparents, in this instance, aren’t seen as authority figures, and grandchildren aren’t viewed by Grandma and Grandpa as tots needing guidance and a lecture or three.

“The grandparent-grandchild relationship is less fraught,” said Dr. Gail Saltz, a clinical associate professor of psychiatry at the NewYork- Presbyterian Hospital/Weill Cornell Medical Center and host of the podcast “How Can I Help?”

“It’s different from a parent- child relationship, where it’s hard to move into the adult space. It’s hard for the parent not to parent, and young adults don’t want to be parented,” she said.

Grandchildren and grandparents have their own discrete needs.

The grandchildren, still in school or in low-paying, entry-level jobs, are looking for deeply affordable housing with tolerant landlords. The grandparents — not as young as they once were — may be contending with decreased mobility, health challenges and isolation.

Further, both sides of the age divide come to the table armed with their own skill sets. The grandchildren can demystify smartphones, Twitter and paying bills online. “They get to feel useful in the relationship. They can help the person they love,” Saltz said. In turn, their grandparents can share family lore and recipes, give the grandchildren a sense of their roots — and a sense of perspective.

Those in their early 20s don’t have the experience to know that life will go on, “and older adults can provide that context,” Butts said. “We’ve survived disasters before. We’ve survived diseases before. We’ve survived recessions before.”

Robert Elson and David, 25, shared a home office and, occasionally, meals. When her grandparents decamped for a few weeks to their condo in Stuart, Fla., David sorted the mail and flagged the utility bills. “I came from living with three friends in a row house in Washington, D.C., to living with people who were a lot older,” she said. “Different energy, right?”

Yes, but good energy. “I feel very fortunate and grateful to have had that housing option,” David said.

Not alone

“The idea of young adults living with grandparents really solves a lot of social issues,” said Rachel Margolis, an associate professor of sociology at the University of Western Ontario in Canada who studies the demography of grandparenthood. “Most older adults want to age in place, and they need help to do so.”

June Iseman, 90, shares quarters on the Upper East Side with her granddaughter Ally Iseman. “My granddaughter moving in with me means I’m not alone,” she said. “Even though she sleeps until 11 and goes to work at noon, the fact is, she’s here. Because I’m not 100% OK in terms of my health, that’s a good thing.”

Of course, grandmates didn’t exactly find each other through Craigslist. Those who choose this particular living arrangement have a long history and a close bond.

Because of family complications, Meghan Shiffer, 20, a college student, lived with her maternal grandmother, Mary Ingraham, for several years during her childhood. In December, when her mother died, Shiffer assessed her options and ultimately decided to move back into her grandmother’s house near Troy, N.Y., this time into a self- contained apartment on the second floor.

“I chose to do this because honestly, my grandmother has always been one of my favorite people,” Shiffer said.

Familiarity seems to breed contentment. “This apartment has been in my life since I was born,” said Ally Iseman, 25, of the rent- stabilized, two-bedroom, two-bath apartment she shares with her grandmother, whom she calls Baba.

“As a baby I was bathed in the sink I’m staring at right now. A lot of my childhood photos and videos were taken here,” said Iseman, a multimedia artist who grew up on Cape Cod, Mass. She made frequent visits to Manhattan to spend time with Baba — “We were always madly in love with each other,” June Iseman said — and ended up in the city for college.

A yearlong stint in California after college wasn’t all Ally Iseman had hoped it would be, and in October 2021 she was back in New York and back at Baba’s place.

Now, it seems, she’s there for good. “She’ll stay on in the apartment after I’m gone,” June Iseman said. “That’s my aim.”

A few weeks

Adam Kantor was raised in Great Neck, N.Y., five minutes away from his paternal grandparents, Lucille and Martin Kantor. “My family was very close-knit, and I spent a lot of time at their house,” said Kantor, 36, an actor and singer whose Broadway credits include “Fiddler on the Roof” and “The Band’s Visit.” “Both of them, Lucille in particular, sparked my love of theater,” he said.

In 2008, during his senior year of college, not long after his grandparents sold their house and moved to a co-op in the Sutton Place neighborhood of Manhattan, Kantor landed his first job on Broadway, a principal role in “Rent.”

“I got a sublet for a few months, and when the show closed I decided to stay on in New York for a bit,” he recalled. It just so happened that his grandparents had a small spare room with a Murphy bed behind the kitchen.

“I planned to stay for a few weeks, but it turned out to be a lot longer,” said Kantor, who, in between out-of-town jobs, was part of the household until 2016 when he bought a small studio apartment in the neighborhood.

His grandfather died in 2013, and “it made me want to be more present for my grandmother,” Kantor said. “I’d take her to Central Park, and we’d go to the theater together.”

Kantor began renting out the studio during the coronavirus pandemic, and recently joined forces with some friends to rent a house in Brooklyn. “I sublet my room because I’ve been doing some shows out of town,” Kantor said.

He could have bunked in the house’s designated guest room, but instead chose to stay with his grandmother “because my relationship with her is so precious to me,” he said.

Traditions

Like David, Cassean Zuniga realized that moving in with her grandparents would smooth the path to higher education. As a high school senior, she decided on the John Jay College of Criminal Justice. But she was looking at a two-hour commute if she continued to live with her parents in the far eastern edge of Queens.

Salvation came in the form of her maternal grandparents, Marciano and Aurora Zuniga, who had a spare bedroom in their Long Island City, Queens, apartment — a mere 20- to 30-minute trip to campus.

It would be a return to the familiar: Years earlier, Zuniga, her parents and her grandparents, who immigrated from the Philippines, had shared a residence.

But the reunion was a bit bumpy.

Zuniga’s grandparents still saw her as a little girl, she said. “The sun would set, and I would start getting texts and calls asking why I wasn’t home yet. They didn’t understand that college classes could go until 7, 8 or 9.”

Still, her grandparents had helped care for her during her childhood. She was not only there for a roof close to campus, but also, “I felt like it was my turn to take care of them,” said Zuniga, who took on several housekeeping chores. “They would say, ‘We feel like you can protect us.’ That felt good.”

It also felt good to see her grandparents from a new — adult — vantage point.

“They would tell me stories about my great-aunts and uncles and their experiences coming to America,” Zuniga said. “My grandfather had been an architect, and he drew me a floor plan of a family house in the Philippines.” She went on: “In the years that I lived with them in their apartment, I knew him as a man who was quite forgetful and sat in front of the TV. But I was able to see that this was a person who had a full career and another life.”

For some grandchildren, moving in with grandparents is a hallowed family tradition.

When Jessica Weiss graduated from Michigan State University in 2011 and moved into the three-level condo owned by her grandmother Pat Hartsell in suburban Detroit, she was greeted by a cousin who was just settling in. Eight other cousins had previously passed through. Once Weiss left Grandma’s place to rent an apartment with friends, she was succeeded by her younger brother, Jacob.

It was a good deal, if not exactly a free ride. “The arrangement was that we didn’t have to pay rent the first year. After that it was a few hundred dollars a month,” said Weiss, who was happy to ante up.

“I think it really helped my grandmother to have the grandkids there,” she said. “She had eight children, and when my grandfather passed away, I think it was the first time she’d ever been alone.

“I was the maid of honor at my cousin’s wedding,” added Weiss, now 33 and an advertising director. “And during my speech I joked about our grandmother being our third roommate and about how she was the wild one.”