Handwashing Can Stop a Virus—So Why Don’t We Do It?


Michael Hallsworth at Behavioral Scientist: “Why don’t we wash our hands as much as we should?

Behavioral science can help identify some of the key barriers. It may also suggest what might make a difference for COVID-19 in the absence of a vaccine, recognizing that there is much we still do not know about this virus.

The first barrier may be a lack of awareness about the effectiveness of soap, water, and scrubbing. People may simply not realize how well specific handwashing actions can prevent the spread of infectious disease. This is why many public health agencies run educational campaigns, which may have varying effects based on how far they take evidence about behavior into account.

For example, last weekend the Behavioural Insights Team (BIT), the organization for which I work, ran a set of online trials with 3,500 U.K. adults to test the impact of various posters on people’s intended handwashing behavior. We found that posters seemed to have stronger effects on people who were already washing their hands more frequently. In other words, the more compliant people got more compliant. Obviously, this is a real problem for infection control.

One specific issue with COVID-19 may be that people’s attention is being drawn to something else instead: face masks. In many countries, face masks in public are uncommon. Therefore, people in these places are more likely to notice when others are wearing masks, since doing so is visible and novel—unlike washing of hands! This may create the perception that wearing a face mask is the priority for preventing infection.

There are benefits from face masks, but we still lack evidence about how they are used or whether they work if worn by people who are not yet infected. At least one study suggests that on their own they may be less effective than handwashing at preventing transmission. And given that there’s a limited supply, face masks need to be reserved for the people and situations where they can do the most good.

Perhaps the main concern is that people may have a risk thermostat, whereby taking protective measures in one area means that they feel greater license to take risks in another. Obtaining a face mask may make people feel more protected and could mean they make less of an effort to wash their hands adequately.

Awareness is unlikely to be enough on its own. We also need to consider availability. In some instances, there are practical barriers to handwashing—water, soap, and drying materials may not be available. People may be aware of what they should do but be unable to follow through. One obvious solution is to increase the provision of alcohol-based hand sanitizer dispensers at locations where handwashing is infeasible. Doing this has been shown to improve hand hygiene on its own.

However, behavioral science shows that not all “availability” is equal: even small increases in required effort may result in a hand sanitizer going unused. Therefore, those providing hand sanitizer should also consider whether they’ve made usage as convenient as possible. How can dispensers be located so people do not have to make detours to use them? How can the dispensers be made more prominent—like the use of color? Where do people normally have to pause, thus making them more open to usage—like waiting for an elevator?…(More)”.