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Changing social norms around sanitation in India

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In some regions of India, toilet usage is lower than expected, leading to open defecation. Professor Cristina Bicchieri and her research team at the University of Pennsylvania have established the Longitudinal Evaluation of Norms and Networks Study (LENNS), with the aim of improving sanitation and toilet usage across India and informing intervention strategies globally. The outcome of LENNS research on social norms and networks is an evidence-based behavioural change intervention to promote toilet usage. Initial feedback has been positive, but further research and testing will be required to assess its longitudinal impact.

Despite advancements in sanitation that increased access to toilet facilities several decades ago, open defecation, i.e. the practice of defecating in the fields, streets, ditches, bushes, riverbeds instead of a sanitation facility, is still prevalent in various parts of the world, especially in low-and middle-income country settings. There are several consequences of open defecation, including being a leading risk factor for spread of infectious disease (the Global Burden of Disease study reported 775,000 premature deaths in 2017 as a result of poor sanitation), women’s decreased safety and environmental contamination, to name just a few. Research shows that availability of sanitation facilities and information alone do not ensure toilet use. There are several reasons why people use a toilet or instead defecate in the open. Some of them are related to cultural and social factors, while others are economic or physical barriers such as lack of affordability or access. There is a need to identify, understand and address the behavioural determinants as well as the practical barriers that influence toilet use.

In India, over the past four decades, the government provided a variety of investments to improve access to toilets. The recently concluded national Swachh Bharat Mission, the clean India Campaign, included new behavioural change strategies to promote the building and use of toilets. Despite these efforts, as confirmed by recent surveys, consistent use of toilets is not universal in many parts of India, especially in rural settings. Professor Bicchieri and her research group at the Center for Social Norms and Behavioral Dynamics at the University of Pennsylvania have studied the social determinants of toilet use and open defecation in Bihar and Tamil Nadu, India in order to improve sanitation practices in peri-urban settings. . With financial support from the Bill and Melinda Gates Foundation, they established the Longitudinal Evaluation of Norms and Networks Study (LENNS). The study aims to understand the social drivers of toilet usage in order to develop a cost-effective behavioural change intervention to promote toilet ownership and sustained use. Insights from the study aim to influence the development and implementation of large-scale policies, interventions and initiatives that will transform social norms and collective behaviours relating to sanitation in India and beyond.

Longitudinal Evaluation of Network and Norms Study

LENNS comprised three phases: the formative and design phase, the implementation phase and evaluation. In the formative and design phase of the intervention, the team conducted in-depth analyses of contextual factors, of relevant social networks as well as people’s beliefs and perceptions, to understand the social drivers of toilet use in the study communities. The insights gained from this phase were used to develop a large-scale behavioural intervention implemented in peri-urban communities of Tamil Nadu. The study applied Professor Bicchieri’s social norms theory and measurement to assess ‘whether’ and ‘how’ the ownership and continued use of toilets can be encouraged and maintained.

“The study aims to understand the social drivers for open defecation within India and develop a norms- focused cost-effective intervention to encourage toilet usage.”

According to social norms theory, behaviour is influenced by the social expectations we hold about what relevant people around us approve and do. For a norm to emerge or change, however, the new behaviour must be observable. It may happen that, although most people have changed their behaviour, it may not be easily observable or apparent to others in their community. In this case, although access to toilet facilities has improved in certain Indian regions, people may still prefer to defecate in the open because they perceive that it is still an acceptable behaviour in their communities. Changing their social expectations by convincing that that most others in their community want to or have already started using a toilet may encourage them to adopt new, healthy behaviours.

In 2017 and 2018, the first two exploratory phases of the LENNS were completed. Through interviews, group discussions and surveys of approximately 5000 respondents, Professor Bicchieri’s team assessed the social barriers and facilitators of toilet usage. The first phase focused on understanding the impact of social networks, while the second phase aimed to understand the social norms behind toilet use and non-use.

The LENNS study aims to improve toilet sanitation and usage. The above photos were taken during the implemementation stage of the study.

Participants and methodology

The LENNS formative research took place within two very different states in India. The first was Tamil Nadu in the south, a relatively well-developed state, with reasonable wealth and educational standards. In contrast, Bihar, in the east, the third largest state by population and, one of the least developed states in India. Despite their differences, both states are working to lower the rates of open defecation. In Bihar, just under half of men and women were open defecating daily. In Tamil Nadu, despite the lower poverty and higher rates of education, around a third of men and slightly fewer women were also still practising regular open defecation. The research took into account different types of settlements and urbanisation within these states. People were included from towns, rural areas, peri-urban communities and slums.

In the first phase over 3,000 people took part in the study. The research team recorded demographics such as health and wellbeing, living situation, access to toilet facilities and defecation habits, as well as information about social networks. In particular, participants were asked who they talk to about toilets and sanitation. The team also asked about their place-based networks (e.g. people they meet at work, in social gatherings, their market place or at their place of worship), types of events they attend and their membership in various local groups. The following year everyone who could be re-interviewed, along with almost 2,500 new participants, were asked further questions about their social norms, particularly their social expectations about various aspects of sanitation behaviour and practices.

Social networks, norms AND behaviours

In line with other research, the team found that the majority of those who owned toilets were using them. Unsurprisingly, they found a socio-economic divide in toilet ownership, where people from poorer and more rural communities were less likely to have access to private facilities. As a result, more than half of the people in rural communities who took part in the study were still practicing open defecation. There were no notable differences between men and women’s defecation behaviour.

Castes are social groups within India that are characterised by lifestyle, occupation and social class. Despite having a higher socio-economic status, some castes were still less likely to own toilet facilities.

In terms of social networks, the research found that people relied upon and trusted family members the most. While they may turn to the government for aid in a short-term economic crisis, when making household changes such as the installation of toilet facilities, they were most likely to seek advice from family members. Interestingly, proximity was a key factor in influencing toilet behaviours. The research found that toilet usage was strongly aligned to that of their neighbours and people living close by. Therefore when designing the behaviour change intervention, it was important to focus on spatial proximity rather than just family ties. It was also more likely that younger people influenced toilet behaviours rather than elders. This suggested that the intervention should focus on targeting younger people first, as they may become the trendsetters for the rest of the neighbourhood.

Pranay Chandra Singh/

When focusing on social norms, it seemed that the normative expectations about others in the community (i.e. if they approved of toilet usage) had little influence. Toilet behaviours were mainly predicted by what people thought those in close proximity were doing (i.e., by their empirical expectations). A similar pattern emerged in terms of women practising open defecation when alone. Their behaviour was much more likely to be predicted by what they thought other women did, rather than by the perception of community approval or disapproval.

Future research and intervention implementation

Whilst this research shows that the beliefs of what others in one’s community do impacts toilet use, further research is needed to understand the type of influence one’s social network has on sanitation decisions.

The research team designed an evidence- and theory-based intervention. The intervention utilised social networks to spread messages, using norm-focused messages to highlight that most people in the community owned and used a toilet. It also provided information to access resources, and connected individuals with community members who would be able to help them achieve their sanitation goals. From February 2020 until June 2021, a community-based trial was conducted across 38 wards in Tamil Nadu. Its impact is currently being assessed by measuring toilet ownership, usage, and improved sanitation. Initial feedback suggests that people are aware of their neighbours’ toilet use and felt peer pressure to build and use toilets. The impact of the behaviour change intervention will be published in 2022.

Artwork summarising the primary aim of the LENNS study.

Unfortunately, the COVID-19 pandemic has affected many peoples’ lives across India, including the finances. For those without a toilet, toilet ownership may become a lower priority. However, for some the perceived threat of disease has had a positive impact on use of toilets. Despite the pandemic, those in the trial regions who were using and maintaining their toilet facilities did report high awareness of the LENNS intervention activities and messages. Initial signs are positive but further testing is required to judge if the intervention will meet its primary objective of improving toilet use and sanitation practices thereby, reducing open defecation across India and beyond.

What will be the next phase of the LENNS?

The learnings from LENNS will be discussed with a wide range of stakeholders including the communities of practice, researchers, policy makers and participants who were part of the study.



    • Bicchieri, C. (2017). Phase 1 Project Report. Social Networks and Norms: Sanitation in Bihar and Tamil Nadu, India. Penn Social Norms Group (PennSoNG), 16.
    • Bicchieri, C. (2018). Phase 2 Project Report. Social Networks and Norms: Sanitation in Bihar and Tamil Nadu, India. Penn Social Norms Group (PennSoNG), 17.

    This article is based on research funded by the Bill & Melinda Gates Foundation. The findings and conclusions contained within are those of the authors and do not necessarily reflect positions or policies of the Bill & Melinda Gates Foundation.


Research Objectives

Dr Cristina Bicchieri and her research team study social norms around toilet sanitation in India.


Bill and Melinda Gates Foundation


Swasti, The Catalyst Group


Cristina Bicchieri is the SJ Patterson Harvie Professor of Social Studies and Comparative Ethics at the University of Pennsylvania, where she is also director of the Center for Social Norms and Behavioral Dynamics. She is a world authority on the measurement of collective behaviours, and has consulted with the UNICEF Child Protection Section, the World Bank, the Ford Foundation, the Gates Foundation, BBC Media and many other groups on behavioral measurement and change.

Cristina Bicchieri

University of Pennsylvania
Philadelphia, PA 19104

E: [email protected]
T: +36 26 393129


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(CC BY-NC-ND 4.0) This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. Creative Commons License

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