On Tuesday, and not for the first time, Joseph R. Biden Jr. described President Trump's reluctance to wear masks as "macho."
Tomi Lahren, a conservative commentator and host for Fox Nation, countered that Mr. Biden "might as well have a wallet with that mask on".
They were among the most direct comments that have linked stereotypes about acting and masculine demeanor to the basic precautions doctors, epidemiologists, and other health professionals recommend to prevent infection from the highly contagious and deadly coronavirus.
The issue has been around since the pandemic began. Some experts studying masculinity and public health say the perception that wearing masks and following social distancing guidelines are unmanly has created devastating costs. The virus has infected and killed far more men than women.
The experts say that best public health practices have clashed with some of the social requirements that men in many cultures must follow in order to assert their manliness: showing strength instead of weakness, showing risk taking, hiding their fear, to be control.
Men's resistance to weakness – and their willingness to take risks – was demonstrated by scientists long before Covid-19. Studies have shown that men are less likely than women to wear seat belts and helmets or to get flu vaccinations. They are more likely to accelerate or drive drunk. They are less likely to seek medical help.
Some initial research shows that a similar pattern is occurring with the coronavirus. Gallup's Covid-19 poll, updated on Wednesday, found that American women are more likely than men to take precautions to avoid contracting the coronavirus, even when wearing masks outside of the home. Other recent polls have found that men give Mr Trump higher marks than women in dealing with the pandemic.
"Admitting that you are threatened means looking weak, so you must have that bravery," said Peter Glick, professor of social sciences at Lawrence University. When you wear a mask, he said, "The underlying message is," I'm scared of getting this disease. "
This is not a new problem for those who work in the public health news field. Stacey Hust, a professor of communications at Washington State University, said sexual assault prevention campaigns often sought to address male ideals and make better behaviors "alpha male worthy".
It tends to be more difficult to reach out to those who identify strongly with traditional male traits. For example, the more someone identifies with these masculine characteristics, the less likely that person is using condoms during sex, she said.
Oct. 11, 2020, 1:13 p.m. ET
"I think that shows very clearly why some men don't wear masks," she said. "It's really about not showing weakness or fear, not showing vulnerability."
Mr. Biden, who has modeled wearing masks and adhered to social distancing guidelines, has repeatedly criticized Mr. Trump for his approach to his personal precautions against coronavirus. In May, he "mistakenly called Mr. Trump male" for refusing to wear a mask and said the precaution meant leadership, not weakness.
At first, Mr. Trump would not wear a mask in public. On very rare occasions, it has been photographed in one but has further downplayed its effectiveness.
He taunted Mr. Biden for mask use and showed him removing his mask on a balcony of the White House when he returned from Walter Reed National Military Medical Center on Monday. He has also continued to host large rallies and other events that do not meet recommended social distancing guidelines.
Theresa Vescio, a professor of psychology and women's, gender and sexuality studies at Penn State University, said Mr. Trump has often participated in "masculinity competitions" as president and candidate.
He's humiliated male rivals – repeatedly referring to former Mayor Michael R. Bloomberg as "Mini Mike" – and defended the size of his penis in the 2016 Republican primary after an attack by Senator Marco Rubio.
And the Republicans have successfully campaigned as a party for men who take their masculinity seriously. In a study with Nathaniel Schermerhorn, a graduate student at Penn State, Professor Vescio found that the degree to which someone supports traditional masculine ideals – including women who traditionally value masculine men – correlates very strongly with identification as Republicans. Polls show Mr Trump gets more support from men than women.
"Republicans have been doing this since 2016, feminizing or suggesting that Democrats have male defects," she said.
Recognition…Kevin Lamarque / Reuters
Many of Mr. Trump's followers admire his aggressive style, said Professor Glick, and see him as a model of male dominance.
It was a missed opportunity at the start of the pandemic. The president could have used that authority to change the perception of masks and other precautions in those who value traditional masculine traits, he said.
"It would certainly have helped," said Professor Glick. "But at this point it is difficult to go back."