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(Part 1) Designing for behavior change: lessons learned from nudging Filipino students to wash their hands

For most people, behaviour change is a difficult challenge to overcome. It’s why new year’s resolution gym memberships go unused, or calendar organizers go dusty. Behaviour is particularly difficult to shift when trying to change a daily habit with clear and immediate costs or inconveniences, but benefits that are only evident later, or are diffused and difficult to quantify. “Present bias” — the tendency of people to value pay-offs closer to the present — is a well-documented phenomenon in human decision-making1. It is particularly difficult for children to weigh future-oriented behaviours, research shows2.

Handwashing is a great example of this phenomenon: a behaviour that is difficult but important to promote. A 2015 systematic review revealed only 26 per cent of people globally washed their hands with soap after contact with faeces3. But during the COVID-19 pandemic, handwashing with soap is more important than ever. It is one of the most effective ways to prevent the transmission of infectious diseases. Even before the pandemic hit, handwashing has been held as one of the most effective measures for reducing respiratory tract infections, diarrhoea, and other diseases4. So as a public health safety measure, it is critical that children build a habit of properly washing their hands.

From our previous work in the Philippines, however, we know that handwashing rates among children in elementary school are very low and very difficult to improve. Even when students knew when and how to wash their hands, and had access to functional toilets and handwashing facilities, they still did not wash their hands. This suggests that behaviour, rather than knowledge or opportunity, is the key barrier to handwashing among pupils in the Philippines. When asked why they did not wash their hands, pupils commonly responded “I forgot” or “I was in a hurry.”

Luckily, in studying how humans deviate from good decision-making, behavioural sciences have broadened the set of tools at our disposal to influence behaviour. One of those tools is “behavioural nudges,” which Thaler & Sunstein define as a change (often environmental) to choices presented “that alters people’s behaviour in a predictable way”.5

In this blog post, we’ll describe how we took broad lessons and insights from available evidence on improving handwashing with behavioural nudges and applied it to our specific context of primary schools in Zamboanga del Norte, Philippines. We’ll discuss some of the challenges we faced designing and adapting nudges to the local context — and the lessons we learned.

Nudges may be a good policy option when the desired behaviour isn’t restricted by lack of knowledge or poor enabling conditions like a lack of functional facilities.

From our previous research, we knew that knowledge and facility access were generally high, so explicitly targeting behavioural barriers to handwashing was a sensible next step.

We were also careful to select schools in Zamboanga del Norte that had adequate handwashing infrastructure such as regular water access and soap availability. This is because nudges primarily influence behaviour. They thus would be ineffective at boosting handwashing rates in schools where the primary barrier is inadequate handwashing infrastructure.

Only a third of the schools in Zamboanga del Norte met our eligibility criteria, which included requirements like pupil-to-toilet ratio below 100 pupils and water availability at least some hours daily. The generalizability of our findings will be restricted to schools that meet these same criteria. In our next companion blog post, we will further explore their policy implications.

While our typical role at IDinsight is one of a policy evaluator, in this case, we designed and implemented the nudges ourselves. Our long-standing partnership with UNICEF WASH and the Philippines Department of Education evaluating the HiFive program equipped us with the necessary local context, knowledge, and trust to execute this program.

We next set out to determine what has worked in previous studies in other geographies and brainstormed how to adapt those lessons learned to the Philippines context. We landed on two types of nudges to serve as reminders and help form habits:

Contextual cues: These cues are changes to the environment where a behaviour is practised to make the behaviour more likely. Examples of this in daily life include candy bars at the check-out aisle, or, in contrast, salads placed at eye-level in school cafeterias. In the handwashing literature, painted footprints or arrows leading from the toilet to the handwashing station are contextual cues that have improved handwashing rates among school children in Bangladesh6 and adults in the US7. These are theorized to trigger reactive processes, which are responses “triggered automatically by a particular kind of stimuli”8 and can lead to habit formation.

Visual reminders: Once kids are brought to the handwashing station, we wanted to include visual cues to provide a reminder of handwashing, and trigger conscious motivators to practice the behaviour. For example, posters that show germs on hands after toilet use would evoke a sense of disgust in pupils, prompting them to wash their hands.

Once we had established our contextual framework and gathered relevant nudges from the available literature, we brainstormed to generate additional nudge ideas and alter current ones. We also listed out assumptions we wanted to test in our scoping visits or pilots. This compilation of ideas and questions helped us effectively plan for the next stage of the design process: refinement and iteration.

Our shortlist of studies took place in various settings and countries with specific bathroom and classroom set-ups. Would we be able to apply their learnings to the types of schools we were implementing in, and how? We conducted school scoping visits to find out. Through this process, we found some nudges were very well-suited to our context, and others were not, leading us to further refine the list and change our nudges in some surprising ways.

Our first observation was that that public school classrooms in Zamboanga del Norte often had separate toilet and handwashing spaces. Students had to take several steps across the classroom from the toilet to reach the place where they could wash their hands.

The long walk from the toilet stall to the handwashing station in a classroom in Zamboanga del Norte ©IDinsight/Nhu Le

This set-up confirmed that adding a footpath leading from toilet to sink (a contextual cue) may be useful since it was easy for children to avoid going to the sink after the toilet.

We also observed that the handwashing spaces were almost always multi-purpose. Called the “health corner,” they were used for everything from drinking water to brushing teeth to cooking and washing dishes. The multipurpose function of these spaces raised the question: how can we make handwashing more prominent? Perhaps in a higher-resource setting, we could have intensively redesigned the space. However, in many of these schools, space is a luxury. We could not relocate activities outside of the health corner space and be sure we weren’t having an unintended negative impact. Furthermore, our intervention was meant to be light-touch, in order to be suitable to other low-resource schools. So, we came up with the idea of installing an arrow pointing to the soap dish (and providing a dish if the class did not have one). This was an inexpensive way to draw attention to the soap and therefore handwashing in the space.

After narrowing down our nudge possibilities through observation, we further refined our nudge design through pilot installations. When thinking of ways to create a footpath, we were initially inclined to only spray-paint footprints, rather than painting a solid footpath and then spraying footprints on top. This is because the painted footpath required substantially more time and supplies. However, our pilot installations showed that the footpath was much more prominent. Additionally, teachers and principals were extremely enthusiastic about the purpose and appearance of the footpath. For that reason, despite the costs, we chose to install painted footpaths with spray-painted footprints.

Pilot installation to compare painted footpath with spray-painted footprints and spray-painted footprints only ©IDinsight/Nhu Le

Once we had made observations and conducted pilot installations, we concluded our formal design process. Here are our final nudges:

Behavioural model of intervention tracing the theory of change of each nudge

Installed nudges in treatment classrooms across Zamboanga del Norte ©IDinsight/Project surveyors

Of course, these handwashing nudges are not really “final.” During the installation process, we solicited feedback from our team to further optimize installation. We also gathered feedback from teachers and principals on the current design, as part of our impact and process evaluations of intervention. In the future, if the intervention is scaled up in other contexts, it would be critical for a more compressed process of piloting, testing, and sourcing materials to take place in these other contexts, to ensure the nudges are suitable for local conditions.

In our upcoming companion blog post, we will share with you how these nudges affected pupil handwashing rates in schools and other insights!

What are your best practices for designing an intervention, whether specific to behavioural nudges or generally? Share them with us below!

Behavioural model citations9

  1. 1. O’Donoghue, T. and Rabin, M., 2015. Present bias: Lessons learned and to be learned. American Economic Review, 105(5), pp.273–79.
  2. 2. Yurgelun-Todd D. Emotional and cognitive changes during adolescence. Current opinion in neurobiology. 2007;17(2):251–7. Available at: Accessed June 11, 2011.
  3. 3. Wolf, J., Johnston, R., Freeman, M.C., Ram, P.K., Slaymaker, T., Laurenz, E. and Prüss-Ustün, A., 2019. Handwashing with soap after potential faecal contact: global, regional and country estimates. International journal of epidemiology, 48(4), pp.1204–1218.
  4. 4. Aiello, A. E., et al. 2008. Effect of Hand Hygiene on Infectious Disease Risk in the Community Setting: A Meta-Analysis. American Journal of Public Health, 98(8), 1372–1381.
  5. 5. Thaler & Sunstein, 2008.
  6. 6. Grover, Elise, et al. “Comparing the behavioural impact of a nudge‐based handwashing intervention to high‐intensity hygiene education: a cluster‐randomised trial in rural Bangladesh.” Tropical Medicine and International Health 23.1 (2018): 10–25.
  7. 7. Blackwell, Calvin, Daniela Goya-Tocchetto, and Zack Sturman. “Nudges in the restroom: How handwashing can be impacted by environmental cues.” Journal of Behavioral Economics for Policy 2.2 (2018): 41–47.
  8. 8. Aunger, Robert, et al. “Three kinds of psychological determinants for handwashing behaviour in Kenya.” Social science & medicine 70.3 (2010): 383–391.
  9. 9. 1. Blackwell, Goya-Tochetto, and Sturman (2018); Grover et al. (2018) 2. Brainstorming post-scoping visit 3. Brainstorming post-scoping visit 4. King et al. (2016); Biran et al. (2014) 5. Biran et al. (2014); Botta et al. (2013); Judah et al. (2009)