Customers, some wearing protective face masks to protect against the coronavirus, wait in line outside a Whole Foods supermarket on 6th Avenue in New York on March 20. Associated Press/John Minchillo

Americans are learning to love the mask. Some of them, anyway.

Days after the federal government advised all residents to shield their faces outside the house to curb the spread of covid-19, people from coast to coast covered themselves up like Old West bandits or would-be surgeons. But many still exhaled blithely, continuing to let their noses greet the sun.

George Katopis of Portland wears a protective mask while putting groceries in his trunk outside Hannaford on Forest Avenue on last month. Ben McCanna/Staff Photographer

On Monday afternoon in New York City — the epicenter of covid-19 cases in the U.S. — most people on the streets and in the few open stores had only their eyes showing, or at least had a mask at the ready. Compliance wasn’t universal. On the Upper West Side near Columbia University, many police and security staff stood at guard points uncovered. The pathways of a crowded park bustled with maskless joggers and dog walkers even as some families swathed every member.

“We, and everyone in our social circle, are taking this seriously,” said Jason Smerdon, 44, a Columbia professor playing with his children on the university’s lawn. While none wore masks, Smerdon had one on him and said he and his wife, a general practitioner at Mount Sinai Hospital, regularly wear them and keep their 2- and 4-year-old children away from others. “At a macro level, it’s disheartening to see the response be different.”

As more information emerges about the way the coronavirus is spread, the global scales are tilting in favor of wearing even nonmedical grade masks when in public. The practice is ubiquitous in much of Asia and legally required in some parts of Eastern Europe. Last week, the U.S. Centers for Disease Control and Prevention joined the pro-mask camp, recommending Americans use cloth masks in public settings where it may be difficult to stay six feet apart.

President Donald Trump responded by saying he’d pass. “It’s only a recommendation,” Trump told reporters on Friday. “You don’t have to do it.”

Those words resonated with Samuel Austerlitz, who was walking maskless in Ewing, New Jersey, on Monday morning, along with at least 20 other uncovered people on foot or bikes. “I would take it seriously if the president wore one — but he says it’s not for him,” the 72-year-old said. His wife, Helen Austerlitz, 58, said she isn’t sure whether to trust the CDC: “First they say don’t wear one and now they say wear one.”

Scott Savage, an associate professor of sociology at the University of Houston, said in an email that people are more likely to mask up if they see others doing it — and if they get a push from the top.

Research shows that people within a group can be highly influenced by other members with higher status, the sociology professor said. That makes Trump’s indifferent response a hurdle.

“The problem becomes convincing people that masks are an effective means to solving a real problem,” he said.

There is still confusion around whom masks protect, and how much. Only medical-grade N95 respirator masks offer full protection, but those need to be reserved for health-care workers and first responders, the CDC stressed in its statement. And while cloth masks may slow the spread of the virus by people who don’t know they’re infected, they can also be dangerous if not washed often and properly.

“Figuring out what to believe, especially in a situation like this with so much conflicting information and so little agreed-upon information, it’s really very difficult for people,” said Michael Baumann, a psychology professor at the University of Texas at San Antonio.

In this case, it’s complicated by the fact that the biggest reason to wear a mask in public is to avoid infecting others when you don’t know you’re sick — and Americans aren’t used to thinking about protective gear that way. In Asian countries where past epidemics have made mask-wearing a norm, Baumann said, the thinking is: “I don’t know if I’m sick, so as a courtesy to you I’m wearing a mask.”

On Monday, not a single person at the Food City in Gatlinburg, Tennessee, was wearing a mask; the only concession to the virus by the town’s sole grocery store were Plexiglass dividers separating cashiers from customers.

“I’m not wearing a mask,” said Pam Papworth, a 55-year-old property manager in Gatlinburg. “My sister is a veterinarian in California, and she sent an article showing that cloth masks are virtually ineffective for this virus. I am washing my hands constantly. I think these handmade cloth masks give a sense of false security.”

In nearby Newport, only a scattering of people walking in the tiny downtown were wearing them, although about a third of the customers in Walmart donned some sort of facial protection: everything from basic paper, to scarves to neck gaiters.

At Denver’s Washington Park over the weekend, masks were few and far between except for the odd bandanna, said Danielle Tuttle, a resident of Centennial, Colorado. She did see one person wearing a ski mask in a grocery store, though: “It was kind of weird.”

Colorado Gov. Jared Polis, D, conducted part of a news briefing wearing a mask emblazoned with the state logo.

“It’s about making it cool so others do it,” Polis said. “Get out those old T-shirts, you know, ‘1998 Guacamole Champion,’ in a trunk you thought you’d never use it again. Get it out of the bottom of your drawer and be creative about making that into a mask.”

In New York, Casey Li, 19, a Barnard student who sat eating lunch on the Low Library steps at Columbia, said she had run out of masks and was waiting for her parents to ship her more from China, where they work. “It’s weird. In one sense we’re such a country of abundance of everything, but how can you not have enough supplies of something so important?”

Meanwhile, in Park Slope, Brooklyn, many people were wearing masks, with one exception: joggers.

Sarah Bertolino, a grocery cashier in Austin, Texas, was provided with masks at work and given a choice whether to wear them. She’s decided she won’t. At 5 feet tall, she feels protected behind the 7-foot plastic shield her employer has erected around every cashier.

As for the mixed messages from Washington — “Honestly, I’ve stopped watching the news at this point,” Bertolino said. “After seeing it in real life every day, I just can’t take it when I get home. My anxiety can’t take it.”