How social norms conserved energy by increasing hotel towel reuse rates by 36%

Intervention · Business


This intervention examines how a behavioral science approach can influence energy conservation behaviors.1 Specifically, the experimenters tested whether messages describing social norms could encourage towel reuse in hotels and condominiums. The study found that combining injunctive and descriptive norms can increase energy-conserving behaviors. This finding was replicated in two more field experiments.


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Rating: 5/5 (Easy to implement, results replicated in multiple settings, significant results)

How social norm messaging led hotel guests to reuse more towels
Control 1.74 avg. towels reused
Mixed normative messages 2.32 avg. towels reused

Key Concepts

Social norms: collectively held beliefs about what kind of behavior is appropriate in a given situation

Injunctive norm: an individual’s beliefs about the level of approval or disapproval of others for a specific action

Descriptive norm: an individual’s beliefs about the actual behavior of others

The Problem

The energy requirements of electricity

Energy demand continues to rise, and the price of oil and natural gas has already risen. To prevent an energy crisis, we must find ways to conserve energy. Of the total energy consumed in the US, 40% is used to generate electricity.2 All forms of electricity use can impact our air, water, and land. 

No lack in knowledge or motivation

Psychologists have been trying to encourage energy conservation since the energy crisis of the 1970s. However, previous interventions have not been successful. A common approach was knowledge dissemination. This tactic assumes people do not conserve energy because they are unaware of the need for conservation or the methods through which they can conserve. However, studies have shown the issue doesn’t seem to lie in a lack of knowledge.3 Another popular theory pinned the issue on a lack of motivation. However, even when individuals acknowledge the environmental and social motivation to conserve energy, it often doesn’t lead to changes in behavior. 

A new approach: social influence

Given how important energy conservation has become, a new behavioral intervention is needed more than ever. Wesley Schultz and his colleagues sought to create a new intervention using social influence. Despite many studies demonstrating social norms’s power to change behavior, few studies examined  whether norm-based messaging can promote conservation. If so, these messages could be a low-cost way to increase energy conservation. Shultz et al. tested this by creating in-room messages for hotel and condominium guests, and measuring how often they reused their towels.


Experiment 1

This phase tested whether normative messaging could encourage towel reuse. The experiment was conducted at an upscale beach resort on 2359 guests. To be included in the study, participants must have stayed for at least two nights. One of six different messages was placed in the bathrooms for guests to see:

  1. A high injunctive norm (“Many of our guests expressed to us their approval of conserving energy…”)
  2. A low injunctive norm (“Some of our guests expressed to us their approval for conserving energy”)
  3. A high descriptive norm (“Nearly 75% of hotel guests choose to reuse their towels…”)
  4. A low descriptive norm (“Nearly 25% of guests choose to reuse their towels…”)
  5. A combined high descriptive and injunctive norm (“Many of our guests expressed to us their approval of conserving energy, and nearly 75% of hotel guests choose to reuse their towels…”) 
  6. Control (“This hotel has initiated a conservation program”)

Each message also informed guests on how to indicate if they wanted new towels. Housekeepers were provided with a data-recording sheet, where they documented s, check-ins, occupant number, and the number of towels taken out of a room per day. Prior to the intervention, baseline data was collected for eight weeks; once the intervention began, data was collected for nine more weeks.

Experiment 2

In this experiment, Schultz et al wanted to replicate the first experiment’s results, but they only tested the combined descriptive and injunctive message with a control message. These messages were placed in condominium units also owned by the hotel.

Experiment 3

This experiment wanted to replicate results from experiment two, while also testing whether referencing a specific group (e.g., previous guests who stayed in the same room) versus a generic group (e.g., guests at this hotel) would make a difference six months after experiment two was completed, the researchers once again used the hotel’s condominiums, and randomly assigned rooms to the control, specific normative message, or general normative message groups.

Results and Application

A 36% increase with combined norms

Overall, the researchers found that normative messaging can impact conservation behaviors. Experiment one’s results suggested that combining descriptive and injunctive norms produced a reduction in the number of towels used, whereas a message with only one kind of norm failed to have an effect. Experiment two again suggested that a combined descriptive and injunctive message could increase towel reuse. Experiment three replicated this effect once more, but also found that specific and generic messages are equally successful at promoting towel reuse.

Three takeaways for future application

  • The study suggests that social norms can even influence private behavior through a simple written message.
  • Only the combined descriptive and injunctive norm message led to more towel reuse. Schultz et al point out that this type of message is also beneficial because the description does not dissuade anyone who already engages in the desired behavior.
  • Surprisingly, there was no difference between a general message and a specific message. The researchers hypothesize that this might be because group identification—which was lacking in this case— might be necessary to induce a difference between generic and specific messages. 
Health & Wellbeing Some studies suggest that normative messages are an effective way to reduce substance use among students.
Public Policy Some research points to normative messages helping increase support for policy proposals, e.g. climate policies, smoking bans, etc.4
Education While teachers usually appeal to injunctive norms to motivate their students, some research points to descriptive norms also having a role to play in improving educational outcomes.5


  • A more diverse sample is needed to understand the effects across diverse groups
  • The intervention improved collective well-being by promoting environmentally-friendly behaviors

Does the intervention demonstrably improve the lives of those affected by it?
Yes, by conserving energy and water.
Does the intervention respect the privacy (including the privacy of identity) of those it affects?
Data was room-based and anonymized. However, it is unclear if hotel management also had access to the data.
Does the intervention have a plan to monitor the safety, effectiveness, and validity of the intervention?
Room for improvement
Although the experiments devised a great system for tracking towel use, it would be beneficial if more indicators of energy conservation were included.

Does the intervention abide by a reasonable degree of consent?
The study did not collect participant consent. Rather, it relied on the hotel’s ability to quantify its own resources, which is standard practice.
Does the intervention respect the ability of those it affects to make their own decisions?
All individuals made their own decisions regarding towel reuse.
Does the intervention increase the number of choices available to those it affects?
Not applicable
The choice to either reuse or not reuse stayed the same.

Does the intervention acknowledge the perspectives, interests, and preferences of everyone it affects, including traditionally marginalized groups?
Room for improvement
It is unclear whether the study consulted consumers or members of marginalized groups. However, energy conservation is partly an equity issue.
Are the participants diverse?
Room for improvement
Participants were predominantly higher-class.
Does the intervention help ensure a just, equitable distribution of welfare?
Room for improvement
Climate change and the energy crisis can exacerbate  inequity and thus, indirectly, the study helps address the issue.

Related TDL Content

Social norms and feedback on water saving: This TDL article describes another instance in which social norms led to an increase in pro-environmental behavior. In particular, this intervention focuses on how normative messaging reduced water consumption in Belén, Costa Rica.

Harnessing Social Norms for Social Good: If you want to learn more about social norms’ power to influence behavior, read this article, which includes recommendations on how to use social norms to encourage social distancing to spread the stop of COVID-19.

Mind the Gap (2/2): Environmental Behavior and Observed Consequences: Normative messaging isn’t the only way to encourage pro-environmental behaviors. Read this article to learn more about behavioral science solutions for energy conservation.


  1. Schultz, W. P., Khazian, A. M., & Zaleski, A. C. (2008). Using normative social influence to promote conservation among hotel guests. Social Influence, 3(1), 4–23.
  2. Environmental Protection Agency. (n.d.). Learn about Energy and its Impact on the Environment. EPA.
  3. Estrada, M., Schultz, P. W., Silva-Send, N., & Boudrias, M. A. (2017). The role of social influences on Pro-Environment behaviors in the San Diego region. Journal of Urban Health, 94(2), 170–179.
  4.   Tummers, L. (2019). Public Policy and Behavior Change. Public Administration Review, 79(6), 925–930.
  5.   Eyink, J., Motz, B., Heltzel, G., & Liddell, T. (2018). Self-Regulated Studying Behavior, and the Social Norms that Influence It [Preprint]. PsyArXiv.
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