Reducing Water Consumption: Why You Care What Your Neighbours Think


When it comes to persuading people to cut down on how much water they use, the behavioural science of "nudging" suggests we may be more inclined to change our habits when we are made aware of what our neighbours think.

Water usage in domestic environments has risen dramatically in the past century, and maintaining access to fresh water is increasingly becoming a major concern, especially in areas prone to droughts. The particular crisis of water scarcity is considered one of the most important issues facing policy makers today. This is the case especially for countries and regions affected by drought, including California in the U.S. and over 50% of India, which is in a critical ‘water-stressed’ area (World Resources Institute, 2015).

This precarious scenario could be dealt with via two potential solutions: increase the amount of freshwater available or decrease the demand for it. As many urban areas of the world lack the ability to increase the supply of fresh water (in some cases resulting in water rationing in Brazil, Colombia, USA, India), the most realistic option is to encourage consumers to conserve water themselves. However, this may be easier said than done.

Changing consumption behaviour, and changing people’s behaviour in general, is a complex task.  Policies designed to do this can often result in inaction, regardless of whether that individual believes it is important to save water at home or not. Many strategies have been introduced, with varying degrees of success, to try and encourage people to decrease water usage in their homes, but which techniques are the most effective in changing people’s behaviour?

Personalised Feedback 

Some of these interventions traditionally focused on simply presenting information to people and expecting them to respond appropriately. This idea is based on ‘the knowledge-deficit approach’, which assumes that people make environmentally harmful decisions due to a lack of information. If people are provided with evidence about how serious overusing water can be, for example, then surely, they will make their own rational decision to reduce water consumption.

However, current research revealed that this technique isn’t sufficient (Seyranian et al., 2014). Criticism arose after many unsuccessful campaigns discovered that, despite individuals reported greater knowledge of environmental issues, people’s behaviour did not actually change. Consequently, other ideas about how to influence behaviour have been developed. The implementation of low-cost behavioural interventions, otherwise known as ‘social nudges’, in public policy reflects the evidence that people are more influenced by indirect suggestions rather than forced compliance.

These indirect suggestions can take many forms and rely on the fact that our choices in life are inherently influenced by bias, habit, past experiences and contextual factors. Unfortunately, this can lead to some poor decision-making skills but can also be utilised positively to promote more preferred behaviours. A nudge takes into account these social, psychological and physical aspects by influencing judgements and changing behaviour in a much more effective and less costly way than traditional regulations and campaigns.

These nudges are used as incentives in decision making. An early example of this is the use of descriptive normative information, such as average neighbourhood energy usage, along with a message conveying social approval or disapproval. Social nudges like personalized feedback have been used to change a variety of consumption behaviours, ranging from electricity, heating, water and even alcohol consumption (Alcott, 2011; Schultz et al., 2007; Dotson, Dunn & Bowers, 2015). Their use in reducing water consumption highlights the potential benefits of applying behavioural theories to real-world situations.

Comparing your lifestyle to others is a common phenomenon and thus the theory of social nudges can be implemented by using this naturally occurring circumstance in a positive way. Do you care how much water your neighbours use? Or would you care more if they knew how much water you use?

According to Schultz and his team, the answer is both. A water reduction intervention was more successful when households were presented with a combination of information on: 1. the amount of water they consumed relative to others in their neighbourhood and 2. whether this behaviour was socially desirable.

Schultz and his colleagues found this personalized normative feedback, in combination with an injunctive message, to be a successful tool in reducing energy consumption in high-energy homes and further proved that this can also be applied to water usage. The use of both techniques simultaneously also removes what is known as ‘the boomerang effect’, when households with lower energy or water use realise their neighbours use more than them and thus feel justified in increasing their usage.


However, despite the usefulness of one particular nudge in one setting, it is important to avoid any generalised assumptions about how that nudge may perform under different circumstances. Whilst behavioural science looks for the patterns and causalities in human behaviour, the influence of individual factors cannot be under-estimated. Hagman et al. studied the acceptance of nudges in different communities across Sweden and the US and found that in reality, a ‘one-nudge-fits-all’ approach does not hold true. Worldview and attitudes of individual difference should be taken into account when formulating nudge policies.

The significance of individual differences when using these personalised normative feedback and inductive messaging techniques is further highlighted by Costa and Kahn’s (2010) research on political ideology. They discovered that the effectiveness of these interventions on electricity consumption varied by as much as 4 times depending on whether the household was a liberal or conservative supporter. Moreover, conservatives are more likely to opt-out of interventions and thus applying these social nudges and normative feedback must be tailored to the individuals involved.

When designing these interventions, in addition to considering the individuals involved, it is also necessary to factor in the effect of the ‘comparison group’. Would you be more likely to care about social disapproval from an unknown family on the other side of your city or from the neighbours down the street? As you might correctly assume, closer proximity to the disapproving audience results in a larger change in consumption, as found by Datta at al. (2015). In an intervention in Costa Rica in 2015, a town-level comparison on water consumption levels actually had no significant effect in reducing water usage, whereas a neighbourhood comparison reduced consumption up to 5.6%. Thus, it is also crucial that the group used as a reference for comparison must be carefully chosen.

Ultimately, current research, such as that presented here, should guide policies on water consumption using the most effective techniques and interventions. Despite the ease of printing information on leaflets or sending email notices about the importance of saving water, these interventions should be completely replaced with more personalised feedback to consumers.

However, can these findings be solely attributed to receiving comparative feedback. An important discussion continues due to research conducted in the UK by Harries et al. (2013), which reveals that the impact of information regarding social norms may have been confounded with the effect of receiving individual feedback. In essence, when households were provided with clear electricity usage in a historical format they were found to reduce their energy consumption by up to 3% regardless of whether they had information about other people’s consumption. Simply being provided with clear, detailed information about their energy use across a fixed period may be enough to change people’s behaviour.

As discussed previously, using personalised normative feedback was a better solution than alerting people to the need to reduce water consumption. It is true that the public are well-aware of how crucial water conservation is, but are they even aware of just how much water they use?

Perhaps making people acutely conscious of their own consumption would also be an effective intervention. Further research must be conducted to confirm whether this information, in comparison to personalised normative feedback, is enough to influence behaviour across a variety of situations and countries.


In summary, social nudging attempts to change behaviour on a large scale and at a relatively low cost. As the evidence reveals, they are much more effective than traditional methods because they incorporate the fact that people do not always act in their best interests, intentions do not match actions and real-world behaviours often reflect unexpected attitudes. However, there is still a lot to be discovered about the long-term impacts of these interventions and how much information people really need in order to change their behaviours.

So, what can you do to reduce your water consumption? It turns out rather than just thinking about how severe a water crisis would be, it may be better to find out how much water you are exactly using and how that compares with your neighbours.


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Costa, Dora, and Matthew Kahn. “Energy Conservation “Nudges” and Environmentalist Ideology: Evidence from a Randomized Residential Electricity Field Experiment.” 2010. doi:10.3386/w15939.
Datta, Saugato, Juan J. Miranda, Laura Zoratto, Oscar Calvo-González, Matthew Darling, and Karina Lorenzana. “A Behavioral Approach to Water Conservation: Evidence from Costa Rica.” Policy Research Working Papers, 2015. doi:10.1596/1813-9450-7283.
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Kit Slatford
About Kit Slatford:

Kit completed her BSc in Psychology at the University of Leeds, and is currently studying a Masters in Environmental Psychology at the University of Groningen. She is currently researching public acceptability of geothermal energy in relation to people's values. Specifically, she is focusing on what information people attend to when learning about new renewable energy sources, which allows her to work with energy companies to help them design effective campaigns.