Sustainability as Behavioural Change: Nudging the Good, Discouraging the Bad

Intentional habit formation can help to drive the adoption of more sustainable eco-friendly behaviours.

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Date Posted

29 Jul 2022


Issue 24, 1 Aug 2022

Singaporeans can do more to adopt eco-friendly habits, particularly in recycling and reducing waste. Perceptions that the governments and/ or businesses have a larger role to play help explain why some individuals do not do more. In a Kantar Public study, 83% of respondents from Singapore said they would accept stricter rules and environmental regulations.1 The assumption underlying this sentiment is that people expect governments and businesses to take the lead, compared to individuals. Short of regulation and legislation, there is a limit to what governments and businesses can do to change individual behaviours.

People expect governments and businesses to take the lead, but there is a limit to what they can do to change individual behaviours.

The gap between people’s beliefs and actions, and their expectations that governments and the private sector play a bigger role, should inform our approach to tackling climate change problems. It is laudable that we have achieved the first step to changing behaviour—recognising the importance of fighting climate change. But we next need to convince individuals to adopt more demanding individual eco-friendly habits, and to find ways to make these habits easier to adopt. The end goal is to see people adopting sustainable and impactful behaviours as part of their regular lifestyle.

Recycling Rate

Figure 1. Recycling Rate of Selected Waste in Singapore (2021). Source: National Environment Agency

Less Talk, More Action Needed

What do surveys say about Singaporeans’ green habits?

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What Does It Take to Make A Bigger Impact?

Some behaviours and actions are more environmentally friendly than others because they reduce the carbon footprint to a greater degree. These impactful behaviours often demand more effort. For such behaviours to be sustained, habits need to be formed.

A defining feature of a habit is when people behave automatically without much deliberation. Psychologist Wendy Wood has found that 43% of what people do every day is repeated in the same context and people slip back into their (good and bad) habits when they are distracted and/or overwhelmed.2

According to Wood and Neal, sustaining behaviour change requires a two-pronged approach: forming good habits while simultaneously breaking existing bad habits.3

Wood and Neal also identify several elements crucial to forming lasting habits.4

  1. Opportunities for the repetition of the same good habit, so that the behaviour becomes automatic. E.g., interventions in school requiring students to recycle all food waste.
  2. Context cues such as the physical environment or times of day to prompt the first step required of the desired behaviour. E.g., setting up a recycling corner next to the waste bin at home.
  3. Rewards to encourage repeated positive behaviours. E.g., receiving a small monetary incentive from recycling a glass bottle.

For recycling, forming good habits alone will not be sufficient, because efforts can be marred by bad habits like incorrect recycling. According to the Ministry of Sustainability and the Environment (MSE), 40% of the contents in recycling bins cannot be recycled because of contamination (e.g., plastic bags with food waste) and/or non-recyclable materials (e.g., styrofoam, tissues, reusables).5 Similarly, SembWaste has reported that approximately 60% of what they handle in their facility cannot be recycled.6

Wood and Neal recommend three strategies to help break bad habits:7

  1. Remove context cues that trigger bad habits by leveraging key moments in life, such as recycling interventions targeting those who have just shifted into new housing estates.
  2. Alter the environment by making it difficult to continue with the bad habit. E.g., requiring recyclables to be sorted by waste type before placing it in the recycling bins.
  3. Vigilant monitoring of behaviour, so that timely feedback can be provided to halt automatic undesired behaviours. E.g., visual cues on the covers of recycling bins to remind what can be recycled.

For habit change to happen, we need to change the context within which we make decisions and act.

Government’s Role in Supporting Habit Change in Singapore

The physical environment around us—homes, shopping malls, the workplace—influences how we behave every day. Our actions are also influenced by other contextual cues like the time of the day, what others do in the same environment, and incentives shaped by government or corporate policies. For habit change to happen, we need to change the context within which we make decisions and act.

In this regard, governments can play an important role in promoting recycling habits by shaping incentive systems through regulations and/or working with businesses to reward positive behaviours, and influencing context cues (e.g., design and location of recycling bins).

Recycle Right!

Seeking to lower contamination in recycling bins, the NUS Zero Waste Taskforce conducted a trial to test a new “Recycle Right” bin design for the recycling of bottles, cans, and notes and cardboard.

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Making It Easy to Recycle Food Waste!

What are the insights from the “Food Waste? Don’t Waste!” pilot programme?

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Empowering Individuals to Nudge Themselves and Others

While governments and businesses can shape the external environment and context cues to encourage good habits and sustain behavioural change, they have more limited influence on habit formation in individual homes. Empowering individuals with the ability to nudge themselves as well as others seeks to resolve this.

Self-nudging is an approach that helps people change their behaviour by getting individuals to design their own environments.8 The appeal of self-nudging lies in customising interventions based on individual contexts, which could bring about better results and afford individuals greater autonomy. A 2018 qualitative study by Tormaet al. on driving sustainable consumption behaviour found that self-nudging was effective in helping consumers better align their actions with their intentions to be environmentally friendly.9 When consumers changed from purchasing at supermarkets to preorder organic grocery delivery services, most believed that they made less impulsive decisions due to the lack of context cues in the supermarkets.

One challenge of self-nudging is that it assumes individuals are effective choice architects, meaning that they can (i) assess their behaviours to identify behavioural barriers and enablers; (ii) understand their environment and context; and (ii) design effective nudges. While this seems to imply that only trained behavioural scientists are qualified to self-nudge, it does suggest that individuals need help in designing effective self-nudges. The public sector can play a role in this effort (see box story on How Self-Nudges Can Encourage More Recycling).

Inspiration for such interventions can be taken from how smartphone applications are often designed to help people with their personal habits such as exercising, healthy eating, and taking care of mental wellbeing. Many habit-forming apps make use of behavioural change techniques such as reminders, goal setting, progress tracking, peer support and incentives. However, Stawarz et al. pointed out that many of these apps primarily focus on tracking behaviours, which is not enough to support habit formation.10 Instead, apps could be designed to help users to select trigger events and set reminders to reinforce intentions.11 For instance, users could choose to sort their recyclables (intention) after dinner (trigger event) and choose to receive a daily notification on the application before the trigger event.

The benefit of empowering individuals need not stop at changing one’s own behaviour. A greater impact could be achieved by involving citizens to play an active role in influencing others to adopt green habits. Through this approach, citizens will see themselves as agents of change. There will also be more problem-solvers in society and they might have a better understanding of the behavioural barriers to adopting eco-friendly behaviours. Like self-nudging, the role of the government here is to equip individuals with the necessary know-how to encourage others around them to adopt green habits.

How Self-Nudges Can Encourage More Recycling

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Nurturing Young Eco-Ambassadors to Help Others Adopt More Sustainable Behaviours (Eco Avengers Unite!)

In 2022, behavioural researchers from MSE and NEA will pilot “Eco Avengers UNITE!” with selected primary schools: a programme to nurture students to become effective eco-ambassadors.

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Sustaining eco-friendly behaviours is not merely about raising awareness about climate and environmental issues and increasing the adoption of easy habits. But awareness and acceptance do mean that half the battle is won.

Nevertheless, the gap between what we intend to do and how we act must be closed. This will depend on us forming appropriate habits to sustain a change in our day-to-day behaviours. In particular, the challenge is encouraging people to form good but difficult habits (e.g., cutting down on unnecessary car trips, walking or taking public transportation, recycling), and to reduce eco-unfriendly behaviours (e.g., incorrectly identifying materials for recycling).

A greater impact could be achieved by involving citizens in influencing others to adopt green habits.

Because the environment and context affect whether a good habit is formed and/or bad habit is disrupted, the responsibility of habit formation should not fall squarely on individuals. The public and private sectors have roles to play in making it easier for people to adopt eco-friendly habits and to see the value in doing so. Governments could also explore empowering individuals to design their own nudges to form green habits and influence others around them. If implemented properly, these have the potential to achieve more than first intended: individuals can apply the same knowledge to other eco-friendly habits with minimal assistance from governments and businesses.

While these approaches may not be straightforward to implement, they can help ingrain important eco-friendly behaviours for the long term, as part of how we address issues of climate action and environmental sustainability as a society.


Charmaine Lim is Lead Researcher at the Institute of Governance and Policy, Civil Service College. Her research interests include evidence-based policymaking and behavioural economics.


  1. Emmanuel Rivière, “Our Planet Issues: Accelerating Behaviour Change for a Sustainable Future”, Kantar Public, accessed May 24, 2022.
  2. Michaela Barnett, “Good Habits, Bad Habits: A Conversation with Wendy Wood”, October 14, 2019, Behavioral Scientist, accessed May 24, 2022.
  3. W. Wood, and D. T. Neal, “Healthy through Habit: Interventions for Initiating and Maintaining Health Behaviour Change”, Behavioral Science & Policy 2, no. 1 (2016): 71-83.
  4. Ibid.
  5. “How to Recycle,” last modified April 19, 2022, accessed May 24, 2022.
  6. Audrey Tan and Mark Cheong, “Recycle-Me-Not: What Happens When the Wrong Things Get Recycled”, The Straits Times, April 18, 2022, accessed May 24, 2022.
  7. See Note 3.
  8. S. Reijula, and R. Hertwig, “Self-Nudging and the Citizen Choice Architect”, Behavioural Public Policy 6, no. 1 (2020): 119-149.
  9. G. Torma, J. Aschemann-Witzel, and J. Thøgersen, “I Nudge Myself: Exploring ‘Self-Nudging’ Strategies to Drive Sustainable Consumption Behaviour”, International Journal of Consumer Studies 42, no. 1 (2018): 141–154.
  10. Stawarz, Katarzyna, Anna L. Cox, and Ann Blandford, "Beyond Self-Tracking and Reminders: Designing Smartphone Apps that Support Habit Formation", in Proceedings of the 33rd Annual ACM Conference on Human Factors in Computing Systems (2015), 2653–2662.
  11. Ibid.

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