Moreover, he said, you’re just never going to get as clean as rinsing with water. Cleanliness matters, since you can get seriously ill from diseases transmitted via feces. Cholera, hepatitis, and E. coli and urinary tract infections are prime examples. Recent studies have found coronavirus in feces, as well.

But while the majority of households in Japan have high-tech toilets capable of cleansing users with precisely directed temperature-controlled streams of water, the rest of the world has been slow to follow.

Blame prudishness and puritanism, at least in part: Bidets, once ubiquitous in France, became associated with hedonism and licentiousness. Marie Antoinette had a red-trimmed bidet in her prison cell while awaiting the guillotine. And during World War II, American soldiers first saw bidets in French brothels, which made them think they were naughty. An often-told joke was that a wealthy American tourist in Paris assumed the bidet in her hotel room was for washing babies in, until the maid told her, “No, madame, this is to wash the babies out.”

But even in France, toilet paper has taken over. “Now, when constructing a new flat, nobody puts a bidet in it,” Dr. Charlier said. “There’s not room for it, particularly in Paris.” Although, when the bidet is incorporated in the toilet, as modern versions are, space is a nonissue. “Maybe there are also psychological reasons we do not embrace the newer technology,” he said.

Which brings us back to the panic buying of toilet paper. Psychologists say it’s more than a little Freudian, what with the anal personality being tied to a need for order, hoarding and fear of contamination. “The characteristics align with obsessive compulsive tendencies, which get triggered when people feel threatened,” said Nick Haslam, a professor of psychology at the University of Melbourne in Australia and the author of “Psychology in the Bathroom.”

Many people are low-level paper hoarders even in the best of times — stuffing takeout menus in kitchen drawers and piling months-old magazines on coffee tables. The pandemic may have just kicked this tendency into high gear, and people are likely latching onto toilet paper because it’s subconsciously associated with controlling filth and disease. “There’s also some evidence that animals hoard nesting materials,” Dr. Haslam said. “So maybe toilet paper has some sort of nesting component as we’re forced into our homes.”

It could also be that, having given up so much of our freedom, some feel, albeit subconsciously, that going without toilet paper would be an indignity too far — a “Mad Max” descent into the realm of the uncivilized. And so, stockpiling of Charmin and Angel Soft will likely continue, even though there are far better ways to clean ourselves and despite environmental groups’ warnings that we’re flushing away our forests. No one wants to get caught without a roll within reach.

Kate Murphy is a journalist in Houston who contributes frequently to The New York Times and the author of “You’re Not Listening: What You’re Missing and Why It Matters.”

The Times is committed to publishing a diversity of letters to the editor. We’d like to hear what you think about this or any of our articles. Here are some tips. And here’s our email: letters@nytimes.com.

Follow The New York Times Opinion section on Facebook, Twitter (@NYTopinion) and Instagram.