The hand-washing gap is a gender difference that has a history. There was a horrible window—between the acceptance of germ theory in the late 19th century and the decline of mortality from infectious diseases (thanks to sanitation, vaccines, and antibiotics) in the middle of the 20th—when American women were told that their families’ health depended on them enforcing the strictest standards of hygiene. In her book The Gospel of Germs: Men, Women, and the Microbe in American Life, historian Nancy Tomes describes the immense pressure on women that the new knowledge of germ theory produced.
The late 1800s were a distressing time for women charged with preventing disease through hygiene. Scientists were learning where many deadly diseases really came from, before figuring out how to prevent or treat them with vaccines or medicines, and messages about the many sources of infection had to have been completely panic-inducing. A 1874 editorial in the reformers’ journal the Sanitarian described all of the parts of the home that could make people sick. It’s a forbidding list: “From the cellar, store-room, pantry, bedroom, sitting room and parlor; from decaying vegetables, fruits, meats, soiled clothing, old garments, old furniture, refuse of kitchen, mouldy walls, everywhere, a microscopic germ is propagating.” After Robert Koch proved that tuberculosis was infectious, and not hereditary, the activist National Tuberculosis Association blitzed people with warnings about contacts in daily life that could spread infection. One example: A National Tuberculosis Association article from 1910, called “Little Dangers to Be Avoided in the Daily Fight Against Tuberculosis,” contained (Tomes writes) “a dizzying array of warnings against drinking cups, paper money, wooden pencils, the prick of an old pin, and the forks supplied at oyster stands.”
Women were always at the center of hygiene improvement efforts. The public health workers who went to tenements and farms to preach this “gospel of germs” as visiting nurses, social workers, and home economists were often women. And under this new way of thinking, mothers were supposed to be the role models for the entire family—teaching hand-washing, stopping men from spitting in the house, and keeping anyone from kissing their babies. The health department in Newark, New Jersey, sent a bib to every baby born in the city in 1929 that had the legend “I don’t want to be sick, please do not kiss me.” (This is a gift I suspect some contemporary parents would appreciate in this year of bad flu.)