What does research show about why men are less likely than women to wash their hands after using the toilet?

The gap is real and consistent

Research repeatedly finds that women wash their hands more than men. Observational data show 15% of men did not wash at all after using a public restroom, compared with 7% of women; when they did wash, only 50% of men used soap versus 78% of women [6][17]. A 2009 UK highway rest stop study found 31% of men and 65% of women washed with soap [7]. A 2003 airport study found 83% of women washed versus 74% of men [27], and observations at public attractions from 2005 to 2010 found hand-washing gaps of 16 to 25 percentage points [29]. A survey found 85% of women said they always wash after using a public restroom, versus 77% of men [5]. Large U.S. surveys during the COVID-19 pandemic also found men reported less frequent hand hygiene than women [4]. A 2016 review found women were 50% more likely than men to practice protective behavior like hand-washing during epidemics [8]. Academic studies similarly report better hand-hygiene compliance in females [2][25], and one study found gender was a significant determinant of handwashing frequency, with women reporting washing more often [40]. A 2019 cross-sectional study specifically examined gender differences in hand hygiene knowledge, handwashing, and hand-drying [1][18].

There is one useful nuance: a public restroom study found men and women washed at similar rates after using a commode (a regular toilet), but men's rates were lower after urinals [3][26].

Why the gap happens: research-based explanations

Researchers have studied the gap far less than they have studied that it exists [46], but the available evidence points to several social and psychological explanations.

• Social norms and being watched. A study of men's hygiene found 90% of men washed when they were around others, but only 44% washed when alone [41][50]. Coverage of handwashing research also notes "social norms change behavior" [51]. Men also seem to respond less to some reminders: a 2003 study found a sign in a restroom increased handwashing among women but did nothing for men [30]. A 2018 survey found gender gaps of 8 to 10 percentage points in whether men and women considered hygienic behaviors important [28]. Other research suggested different messages work for each gender: disgust-based messages ("Soap it off or eat it later") resonated with men, while knowledge-based messages ("Water doesn't kill germs, soap does") motivated women [16][49].

• Socially programmed care roles. Health psychology researcher Susan Michie said the gap is likely socially programmed behavior, not genetic, and that women are more focused on care than men, including childcare, household care, and personal care [9][10][19][20][42][43].

• History and gendered responsibility. Historian Nancy Tomes says the hand-washing gender gap has a long history dating back to when germ theory entered public consciousness in the Victorian era [13]. Women especially were told their family's health depended on the highest level of hygiene [14][23][31][47], and mothers were expected to be role models for the whole family in hand-washing [32]. The message that "make a mistake and your kid will die" still resonates with mothers today [15][24][48]. This legacy is described as a "shadow presence" that still shows up in household cleanliness standards and the persistent hand-washing gap [33].

• Masculinity and a sense of invincibility. Researcher Carl Borchgrevink suggested men's lower handwashing could come from a sense that men are too macho to fear germs [11][21][44]. Some men who skipped handwashing told researchers "I'm clean, I don't need to wash my hands," and seemed to have a sense of invincibility [12][22][45].

• Disgust sensitivity. Research finds women are consistently more disgust-sensitive than men [35][36], and studies have hypothesized and tested that women would be more sensitive to disgust than men [38][39]. Because disgust increases the chance of handwashing [34], this is seen as another relevant piece. One study also links food disgust sensitivity to disease-preventing behavior and notes that gender differences exist in preventive behavior [37].