Since moving to a high-rise building along the Southwest waterfront a few weeks ago, Nick Hamlin and his wife, Lauren Pengrin, have asked one big favor of their neighbors: to help push a couch into their apartment.

“I realized that if they opened their doors, we could get extra space to push it in,” Hamlin said. “They were really great about  helping us.”

Since then, it’s been little more than a “Hi” and “Bye” relationship. Their neighbors smile; they smile back. Some small talk, and that’s about it.

“I like them, but I don’t know them,” Hamlin admitted. “Wow — the more I think about it, the more I realize how little I know them.”

District residents talk to their neighbors, but they don’t feel like they truly know them, and they certainly don’t regularly ask each other for help. Those were the findings of a civic-engagement report the city commissioned through the National Conference on Citizenship. The group, as instructed through a  law passed by Sen. Edward M. Kennedy (D-Mass.) in 2009, annually assesses civic engagement in all 50 states and the District. Among the indicators: volunteering, voter participation, discussions about politics and feelings about one’s community.

Researchers found that about half of D.C. residents regularly discuss politics — well above the national average of 29 percent. About half frequently talk to their neighbors — slightly above the national average of 43 percent. But only one in three residents said they would “trust most or all” of the people around them, way below the national average of 56 percent. Only 11 percent would regularly ask them for a favor.

The report concludes that if the District were to be compared with the 50 states  — a dubious thing to do, demographically —  it would rank as the least neighborly in the nation.

“The difference was stark,” said Ilir Zherka, executive director of the National Conference on Citizenship. “We don’t see such a big gap anywhere else.”

The distinct lack of trust seems especially apparent in some rapidly transforming D.C. neighborhoods, where tension can fester between older and newer residents. It arises during small grievances, such as when impromptu soccer games get kicked out by formalized recreation leagues, or large ones — like low-income housing projects being torn down to make way for urban renewal projects.

The city has established an office to promote volunteer efforts in which neighbors can help neighbors — an effort that offers an anecdotal counterpoint to the study’s findings. Last winter, for example, nearly 200 volunteers signed up during the cruel weather to do a big favor for seniors: shovel their sidewalks and steps.

“Service transforms communities for the better and, in that process, builds greater relationships within those communities,” said Jeffrey Richardson, executive director of the Mayor’s Office on Volunteerism, which helped commission the report.

Hamlin’s Southwest neighborhood is a mix of high-rises, low-rise projects and townhouses along the Potomac River, anchored by a snazzy new Safeway. On a recent night, few residents there could say they fully trusted everyone around them, and even fewer would regularly ask someone for help. Their hesitance was driven by feelings of self-reliance and safety. Sometimes it was racial; sometimes generational.

One woman in her 30s said she couldn’t possibly trust her neighbors “because some of the ones who have been here for a long time are bad neighbors.” She did not want to be identified because of safety reasons. “One of my friends came over three weeks ago, and her bike was stolen,” she said. “And I am pretty sure it was stolen by someone who lives in my building. Why would I have trust in them?”

One block from the Safeway, Barbara Randolph, 72, recalled a time when the only thing residents could do was trust each other. More than a half-century ago, she moved to Greenleaf Gardens, a subsidized housing complex of two-story, attached brick homes.

She raised eight children there. No one had a lot of money, so they would loan each other $20 or watch each other’s kids. When Randolph was hospitalized for four months in 1981 after suffering a stroke, her children never missed a meal.

“All my neighbors kept on bringing them food,” Randolph said. “Because that’s what you do when you’re low-income. You look out for each other. You’re in survival mode.”

Randolph said she had no idea why other neighborhoods wouldn’t do the same.

Greenleaf Gardens still houses multigenerational, low-income black families. But across the street, the neighborhood is increasingly made up of white, affluent, first-generation Washingtonians.

One of them, Dan Sullivan, stepped out of his shiny new apartment to smoke a cigarette shortly after Randolph finished speaking. He’s white, 39 and has lived in all parts of the city over 20 years. A “polite city” is how Sullivan described the District, but one where residents are constantly rushing and can be obsessed with their professions. And with that that, sometimes, community camaraderie falls by the wayside.

“I think especially now, there’s just so much tension between black and white, and with gentrification,” said Sullivan, an administrator for the International Brotherhood of Teamsters. “We live in a complex city.”

Still, he said the way to create trust is not that complex. About a year ago, he asked a big favor from an older, black woman across the street. “Where do you go to church?” he asked. She told him and invited him to tag along.

“She introduced me to all her friends, and said, ‘He’ll be coming to church with us from now on,’ ” Sullivan said.

So now, that’s what he does.