In 1847 Ignaz Semmelweis showed that hand washing of midwives helped to reduce significantly mortality rate of childbed fever, from aroud 10 percent to around 1 percent, although at the time, he became rather unpopular for it. In 1890, Robert Koch demonstrated that anthrax was caused by the bacterium Bacillus anthracis and provided evidence for Pasteur's germ theory. Despite the implications for hygiene being so clear, it is again a case of theory against practice as case studies show.
Results from studies on hand washing behavior vary, debited in part to experimental protocol. Amanda Stinson concluded in her article "Hand washing behavior of women in public bathrooms", that due to an increased self-awareness, subjects were more likely to wash their hands when someone else was present washing their hands. Stinson distinguished between three conditions in her study on hand washing behavior of women:
- No observer was visible
- A person is talking on the cell phone next to the faucet
- A person is washing her hands
She found that overall only 40 percent of young women washed their hands. In the hand washing condition (3), the subjects were more likely to wash their hands, 56 percent, while in the cell phone condition (2), subjects were less likely to wash their hands 27 percent. Stinson also found a strong and highly significant negative correlation between the time of night and whether or not the subject washed her hands.
In some studies it is not very clear whether the social factor mentioned above was taken into account so it is difficult to compare data over different studies. It also becomes clear from another study (see below), that age and education could be correlated variables. I therefore mention only one more study to compare men and women's hand washing behavior.
In the study "Gender and ethnic differences in hand hygiene practices among college students" by Anderson and colleagues it is not completely clear how they observe people in restrooms, however they make no mention of controlling the social variable and I would speculate that the difference from the results above could be explained in terms of social pressure.
What they found is that men washed their hands in 38 percent of cases and women in 62 percent,hand hygiene in females would be better than in males. In the discussion, Anderson and colleagues reference earlier similar evidence. They provide the argument that females' higher compliance could be associated with their tendency to practice socially acceptable behaviors. This however would also mean that having somebody watch you in the bathroom would have a stronger effect on women than on men, so that the question of who is more hygienic, men or women, cannot be answered conclusively.
Interestingly, Anderson and colleagues found that the minority students exhibited better hand hygiene practices than the Caucasian students. Comparing other studies they find that hand washing behavior in this college student population was only slightly higher than in populations of middle school and high school students. As for adequacy of hygiene, they report that only a small proportion of those who washed their hands did so for 20 seconds.
To come back to the original question: should I take the peanuts? I think that's a question of priority: just how hungry are you?Enjoy those peanuts. At least as long as you can. Please leave a comment below for questions and suggestions. If you liked this article you might also want to read about the speed of nail growth. [ Read more... ]