Will the Apple Watch’s Hand-Washing Reminders Actually Work?

Here’s how experts say to design ‘nudges’ that actually work — and their thoughts on Apple’s new feature

Apple Watch on a table.
Apple Watch on a table.
An Apple Watch Series 3 smartwatch. Photo: Neil Godwin/T3 Magazine/Future/Getty Images

I always thought I was pretty good at washing my hands, but when the pandemic began and hand-washing became an issue of life and death, it became starkly obvious that a quick scrub with hand soap was not enough. I got onboard the intense, 20-second hand-washing train, and I probably haven’t had hands this clean since I left food service.

But lately, I’ve felt myself slipping up, washing my hands for 10 seconds instead of 20, then having to go back and do the whole thing over again. As New York has begun to ease up on its stay-at-home orders, I’ve subconsciously followed suit by drifting back to my lazy hand-washing habits. It’s taking a conscious effort to remember to sing happy birthday to myself twice in a row before I’m done at the sink.

So when Apple announced at WWDC that it’s created an Apple Watch feature specifically to encourage better hand-washing habits, I was intrigued, but dubious that it would have much of an effect. How much of an impact can a vibrating Apple Watch with a bubble-letter countdown have on my hand hygiene? And for that matter, how effective are any tech apps that “nudge” us towards better, healthier behavior?

I’d set out hoping for a straightforward answer to the question — nudge type A tends to elicit greater results than nudge type B — but, like human behavior itself, there’s a complex array of factors that make for a successful nudge. From the research that does exist, it seems that the effects from technological health and behavior interventions — like the Apple hand-washing feature and notifications from fitness apps — are likely to be temporary. In other words, the Apple Watch app would probably assist in encouraging better hand-washing behavior — for as long as I was wearing the Watch, at least. But in all likelihood, I’d go back to my bad habits once I’d given up the device.

According to Paul Sherman, an assistant professor of user experience design at Kent State University, a lot of the time, product designers operate by what he calls a “hit record model or the movie model — throw everything at the wall and see what sticks.” And that’s because, Sherman says, we don’t exactly know which interventions will work best. There’s a lot of guesswork and experiments going on, rather than designers relying on decades of wisdom and research to guide them.

This isn’t to say product designers are completely operating in the dark. Research shows, for example, that opt-out or default settings are an especially successful form of nudge, as they compel the user to behave in a particular way without the user having to think too hard about it. Dennis Hummel, a doctoral researcher at Karlsruhe Institute of Technology in Germany whose research focuses on digital nudges, says defaults are one of the better ways to nudge people in one particular direction. One 2016 study, he says, “used defaults in emails by automatically signing up individuals for vaccine treatments, thereby doubling the rate of appointments.” A real-life example of the efficacy of defaults, he says, are automatic organ donation sign-ups. “In those countries where individuals have to opt-out from being a donor, the organ donation rates are much higher.”

Defaults are a form of what’s known as “implicit nudges,” which push people to make certain choices without them being actively aware they’re doing it. A printer that is automatically set to double-sided printing is an example of an implicit nudge to encourage people to save paper.

An explicit nudge prods users toward certain proactive actions or behaviors. To continue the printer example, an explicit nudge to get people to save paper would be if your computer asked you if you wanted to do double-sided printing every time you wanted to print something.

The Apple Watch hand-washing feature uses explicit nudges when it vibrates as wearers enter their homes, reminding them to wash their hands. When the Watch senses the user has begun to wash their hands, it will initiate a 20-second countdown, complete with cute text made to look like bubbles appearing in the Watch face. If the user stops washing their hands before the 20 seconds is up, they’ll receive an alert to keep washing.

These types of nudges are trickier to successfully implement, because the user is made aware that the product is trying to make them do something that they may or may not want to do. Even if they think they want to do the thing, they may not really have the motivation to do so. In effect, defaults and other implicit nudges ask less of users, so the user is less likely to express resistance to, for example, double-sided printing if they don’t have to take action and the printer is set. A printer that asks you if you want to do double-sided printing, however, will see less success at getting you to save paper.

But certain explicit nudges can work, at least for as long as the user decides to engage with it. A 2019 study out of Cornell looked at the impact of vibrations in compelling users to stop using Facebook. In the first week, participants used Facebook normally; in the second, their phones would vibrate once they’d exceeded their daily Facebook limit; in the third, the phone once again went back to operating as normal. The vibrations encouraged users to exit out of the Facebook app, though they didn’t stop users from opening it in the first place. While the time spent on Facebook went down by 20%, the number of times users opened the app didn’t. In the third week, once the vibration nudges were no longer in effect, participants went back to their old Facebook habits.

A 2018 study investigating what kind of push notifications were most successful at encouraging exercise found that what users needed from the app depended on how long they’d been using it. Newer users were more likely to stick with the app when notifications contained suggestions (for example, “Walk 2,000 steps to reach your daily activity goal!”). After a while, though, users were more engaged and responsive when notifications contained insights instead (“You’ve walked 8,000 steps today”).

Finally, a 2019 review looked at all the ways technology can nudge users toward certain behaviors, and found that no one type of nudge was a guaranteed hit or miss; rather, the nudge’s success was contingent on the context, the audience, and a whole host of other factors. The study authors point out that many health and behavioral modification apps have high abandonment rates, which is something researchers and designers are still trying to understand how to counteract.

Still, researchers I talked to had high hopes for the Apple hand-washing app, for the duration that people decide to use it, anyway. “I strongly believe that this timely nudge has the ability to establish proper washing habits,” says Ana Caraban, a PhD candidate at the University of Madeira in Portugal, who conducted the 2019 review. But she thinks the feature would be more effective if it wasn’t opt-in. “Prior research has found lower adherence in opt-in than opt-out strategies,” she says. “Because the motivated behavior resembles people’s best interests and has a crucial role in the transmission of [Covid-19], I would have chosen an opt-out approach to increase adherence to the behavior.” The feature, basically, would benefit from the inclusion of that implicit nudge, so that adoption isn’t another hurdle for it to clear.

Michael Sobolev, a co-author on the Facebook vibrations nudge study, is currently working on his own study on technology and hand-washing. “One of the most promising applications of digital nudging is location-based reminders,” which the Apple Watch app — which will remind you to wash your hands when you get home — employs. “This nudge will also likely help people with the intention to wash hands frequently but often forget to do so.”

This won’t work as well for lazy people who simply don’t want to wash their hands, though, he says. For them, the app would need some kind of “commitment device,” such as vibrations or other reminders that don’t stop until the Watch senses that you’re washing your hands. A similar real-life intervention would be the beeping noise that starts when you sit in your car and doesn’t relent until you’ve buckled your seat belt, which actually inspired Sobolev’s Facebook vibrations nudge study in the first place.

It’s only the latest and greatest on a list of apps geared toward improving health and hygiene during the pandemic (and, theoretically, beyond). JalapeNO!, a Fitbit app designed by a University of Hawaii computer science professor, causes the Fitbit to vibrate whenever it senses your hand near your face. Wash Your Hands! sends customized notifications that remind users to, you guessed it, wash their hands. And like the Apple Watch app, the Samsung Galaxy Watch has an opt-in hand-washing app, complete with reminders and a countdown.

If I had an Apple Watch, I’d absolutely turn on the hand-washing feature, though I’d temper my expectations (my own lack of faith in the life-changing capabilities of apps is well documented). Like most other apps meant to compel you to drink more water, exercise, get offline, or otherwise make you a better person, it’s little more than a band-aid solution.

I’m a columnist for OneZero, where I write about the intersection of health & tech. Also seen at Elemental, The Atlantic, VICE, and Vox. Brooklyn, NY.

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