Belief, like any other moving body, follows the path of least resistance.

Samuel Butler

Imagine that you have agreed to participate in an experiment on visual discrimination. Upon arriving for the study, you are asked to take your place at a table at which five other participants are seated. As you take your seat, the experimenter explains that this study will involve making perceptual judgments regarding the lengths of four lines. He then projects an image on the screen at the front of the room. On the left side of the screen there is a line labelled “X.” On the other side of the screen are three lines, labelled “A,” “B” and “C.” Your task, he explains, is a simple one: to select which of lines “A,” “B” or “C” is equivalent in length to line “X.” The experimenter then proceeds to show a variety of slides. For each slide, the other participants and yourself are asked to select the line that is equal to “X.” After several slides, you are beginning to yawn and wonder how someone ever received a grant to conduct this research.

On the next slide, however, something unexpected happens. In response to the set of lines on the following page, the first participant selects line “C” as the line that is equal to “X.” You rub your eyes and look again. Yes, she did say “C”but clearly that is wrong, you think to yourself. Your train of thought is broken as the next participant also reports that line “C” is equal to “X.” After the third, fourth, and fifth participants also select “C,” you begin to question your own visual abilities, mentally make a note to have your eyes checked and then utter what a moment ago was unthinkable. “Line C,” you hear yourself saying, “is the correct choice.”

When Solomon Asch conducted this study, approximately 75% of the participants altered their answers at least once to concur with the incorrect answers of others in the group, who, as you have by now surmised, were accomplices of the experimenter.1 Perhaps you are thinking that these visual discriminations were difficult enough to lead participants to question their selections. Unfortunately, they were not. When participants were left on their own to select which of the three lines was the correct match, the correct line was selected 99% of the time.

Asch’s research is both surprising and troubling. In response to the findings, he wrote, “That reasonably intelligent and well-meaning young people are willing to call white black is a matter of concern.” Asch’s findings are not unique, however. In a variety of settings, people have been found to alter their answers to be in line (no pun intended) with normative, though clearly incorrect, answers given by others.

What is fascinating about Asch’s study, and other research on conformity, is that the tasks are often completely inconsequential. In the larger scheme of things it simply doesn’t matter which of the lines is equal to “X.” Nevertheless, people looked to the behavior of those around them to determine how they would respond.

Asch’s research underscores the important role that other people have upon our own behavior. To date, however, too little attention has been given to the significant impact that norms can have upon the adoption of sustainable behavior. If we are to make the transition to a sustainable future, it is critical that we are able to develop a set of societal norms that support sustainability. This chapter will introduce you to research which demonstrates the powerful influence that norms can have upon sustainable behavior, and provide guidelines for integrating the use of norms into the programs you deliver.

Social Norms and Sustainable Behavior

Several studies have documented the impact that social norms can have upon individuals engaging in sustainable behavior. At the University of California Santa Cruz’s athletic complex, the male shower room has a sign that encourages that showers be turned off while users soap up.2 More specifically, the sign reads: “Conserve water: 1. Wet down. 2. Water off. 3. Soap. 4. Rinse.” This sign apparently had little effect on behavior. On average, only 6% of users were found to comply. One possibility was that people simply didn’t see the sign. However, a survey of a random sample of students demonstrated that 93% were aware of the sign and its message.

Elliot Aronson and Michael O’Leary reasoned that students might be far more likely to comply with the sign if they observed another student following its instructions. To test this possibility, an accomplice entered the male shower room in the athletic complex, proceeded to the back of the room and turned on the shower. When another student entered, the accomplice turned off the shower, soaped up and then turned on the shower once more to rinse off. All of this was done with his back to the other student and without eye contact. When the accomplice modelled water conservation in this way, the percentage of students who turned off the shower to soap up shot up to 49%. Furthermore, when two accomplices modelled water conservation, the number of people who followed suit rose to 67%.

It is important to note that the changes in behavior observed in this study were not brought about by punitive measures. No “shower police” intervened if students did not turn off the shower while soaping up. It should be noted that two community-based social marketing strategies are employed in this study: prompts (the sign) and norms. While the sign by itself was ineffective in altering the behavior of those using the shower room, when it was combined with the norm, behavior changed dramatically.

The following study illustrates the importance of two types of norms: injunctive and descriptive. Injunctive norms provide information on what behaviors are approved or disapproved of, while descriptive norms indicate which behaviors are normally engaged in. Picture yourself leaving the local library and walking toward your car in the parking lot. As you get closer to your car, you notice that someone has left one of those annoying flyers not only under your windshield wipers, but everyone else’s as well. You remove the flyer and crumple it up, but do you toss it on the ground? I am well aware that most of the people who will read this book will take the flyer home and put it in their recycling container, but what would most other people do in this situation? The answer, it turns out, depends upon what those around them do.

In a series of studies, Robert Cialdini and his colleagues placed flyers on every windshield in a library parking lot.3 In one condition, as library patrons made their way back to their cars an accomplice walked past, picked up a littered bag and placed it in a garbage can. In the control condition, the accomplice simply walked past and did nothing. What impact did these simple acts have upon the library patrons? For those who observed the littered bag being picked up and thrown in the garbage (an injunctive norm), virtually no one littered the flyer. However, when the accomplice simply walked past and left the bag on the ground, over one-third threw the flyer on the ground! In a related study, Cialdini and his colleagues removed the injunctive norm of having an accomplice walk in front of the library patron and stop and pick up the garbage. In this follow-up study, they simply manipulated the number of flyers that were strewn about in the parking lot (descriptive norm). When the parking lot was littered with flyers, the library patrons littered as well. However, when only one flyer was littered in the parking lot, patrons littered significantly less. This research demonstrates the unique contributions that injunctive and descriptive norms can make to behavioral change. However, are there contexts in which we should be careful in using injunctive or descriptive norms?

Using Norms Effectively

The Iron Eyes Cody television ad is one of most highly regarded public service announcements (PSA) in the United States. Robert Cialdini notes that the ad was rated as one of the top television commercials of all time by TV Guide. It aired repeatedly in the 1970s and 1980s and garnered millions of dollars of free airtime.4 Despite the widespread recognition that the PSA received, Cialdini suggests that the spot was likely not as effective as previously thought. The PSA showed a traditionally dressed American Indian canoeing along a river which is strewn with garbage. When he comes ashore he witnesses a bag of garbage thrown from a passing car. The spot finishes with a close up of his face with a tear rolling down his cheek.

Cialdini notes that the creators of this ad inadvertently placed injunctive and descriptive norms in competition with one another. In the PSA, the tear rolling down his cheek serves as an injunctive norm in which the act of littering is clearly disapproved of. However, the plethora of garbage through which he canoes serves as a descriptive norm, showcasing that many people litter. Over the last several years, several intriguing studies have investigated the impact that descriptive and injunctive norms can have upon sustainable behavior. Furthermore, they have shown why programs that utilize norms have to be carefully constructed to avoid inadvertently encouraging a behavior we wish to discourage.

The Ad Council, “People Start Pollution. People Can Stop It.”
© 1971, Keep America Beautiful, Inc.

If an undesirable behavior, such as littering, is a frequent occurrence, showcasing the behavior may encourage others to engage in that action. For instance, in Arizona’s Petrified National Forest, visitors have traditionally been greeted with signs that proclaim, “Your heritage is being vandalized every day by theft losses of petrified wood of 14 tons a year, mostly a small piece at a time.” Unbeknownst to the park administration, the use of these signs was actually encouraging visitors to steal by displaying that many people in the past had taken home mementos.5 Cialdini and his colleagues noted that the park administration had “stimulated the precise behavior they had hoped to suppress by making thievery appear commonplacewhen, in fact, only 2% of the park’s millions of visitors have every taken a piece of wood” (p. 8).7 To investigate the impact that descriptive versus injunctive norms might have on the theft of petrified wood, they devised a study which involved alternating an injunctive and descriptive sign in three high-theft areas in the park. Each sign was used for an equivalent amount of time in each location. Similar to the sign that was already in use, the descriptive sign asked visitors not to steal the wood and showed several people stealing wood. In contrast, the injunctive sign also requested visitors not to take wood, but showed only one person doing so. What impact did the two signs have upon wood being stolen? When the descriptive sign, which depicted several people stealing wood was used, more than twice as many visitors stole wood from the park.8

In designing programs that make use of norms you need to carefully consider the possibility that providing descriptive information could actually decrease the desirable behavior amongst some individuals. This possibility has been carefully explored in several studies by Wes Schultz and his colleagues. In one study, households received information regarding energy conservation via door hangers.9 Some households received information on their energy consumption along with information on whether their energy use was higher or lower than the neighborhood average (descriptive norms). In contrast, others received this same information along with a hand-written smiling emoticon if they used less than their neighbors and a sad emoticon if they used more (descriptive and injunctive norms combined). Interestingly, those households who received information that indicated that they were using more energy than their neighbors reduced their energy use. In contrast, those households who received information indicating that they were using less than their neighbors increased their energy use. However, when households who were using less than the neighborhood average were praised for their low use, they continued to use less energy.

Building on this research and approach, Opower has worked with utilities across the U.S. to provide descriptive and injunctive normative information regarding energy use. Households are provided with information on their energy use relative to other homes in their neighborhood. Over 1 million households presently receive normative feedback on their energy use and this feedback has been associated with a 2.4% reduction in residential energy use.10,11

For norms to be effective they need to be internalized by people. That is, people need to view the behavior which the norm prescribes as the way they “should” behave. Several studies demonstrate that it is possible to influence the acceptance of such norms. Joseph Hopper and Joyce McCarl Nielsen believe that an important motivation to recycle is the belief that it is simply the “ right thing to do” (a social norm), despite the fact that it takes time and can be inconvenient. Further, they expect that this norm is most likely to develop through direct contact between people rather than through campaigns that rely upon prompts or information alone. To test these assumptions, the authors arranged for a sample of homes in Colorado to be divided into three groups.12 In one group, households were visited by a volunteer block leader who spoke with them about curbside recycling, encouraged them to recycle, and then provided a reminder notice several days before the recycling collection date. In contrast, in the prompt group, households received a reminder notice a few days before the collection day, while in the information group households received a flyer that described the recycling program, indicated what items were acceptable and provided the collection dates. Those households who were visited by a volunteer block leader recycled nearly a third more often than households who received prompts and nearly three times as often as the homes who received the information flyer (further evidence of the ineffectiveness of information-based campaigns in bringing about behavior change). Not only were the volunteer block leaders most effective in altering behavior, but they alone had an impact upon norms. In comparing survey results from before and after this campaign, households who were visited by a block leader were more likely to report that they felt upset if they discarded recyclable materials and that they felt an obligation to recycle these materials. The prompt and information strategies had no impact upon these beliefs.

Many anti-littering campaigns have as their central message that littering is simply not acceptable behavior. When Oklahoma City initiated an anti-littering campaign, community norms regarding littering changed substantially. Prior to the campaign, 37% of the community indicated they would feel guilty if they littered. Two years following the campaign that figure had risen to 67%. The number of people who believed they would lose the respect of others if they littered nearly tripled in the same time period.13

Finally, normative strategies are likely to be particularly effective when people are being asked to change their behavior or adopt a different lifestyle. In these cases, behavioral research suggests that direct contact in which social norms, modelling (see chapter on effective communication), and social diffusion occur may be particularly important.14

A Checklist for Using Norms

Follow these guidelines in using norms:

  • Make the norm noticeable.
  • Present the norm at the time the targeted behavior is to occur. For example, upon entering a supermarket, customers could be greeted by a prominent display that indicates the percentage of shoppers who purposely select products that favor the environment.
  • Use norms to encourage people to engage in positive behaviors (rather than only avoiding environmentally harmful actions).
  • Be careful using descriptive norms when an undesirable behavior is common.
  • Combine descriptive information with praise (injunctive norm) when someone is performing the sustainable behavior better than average.

Below are a variety of suggestions for using norms to promote sustainable behavior.

Examples: Using Norms to Foster Sustainable Behavior
Agriculture & Conservation
  • Ask farmers who are committed to engaging in watershed and/or biodiversity protection for permission to install signs along the edge of their property showcasing the actions in which they are engaged. If possible, these signs should be placed in locations where they will be visible to the greatest number of other farmers (e.g., alongside the busiest highway).
  • Attach gas mileage bumper stickers to very fuel-efficient cars.
  • Attach decals to energy-efficient products in stores that indicate the number of people who believe it is important to purchase products that are more energy efficient.
  • Provide information in the foyer of an organization regarding the percentage of staff who use mass transit, car pooling, walking or bicycling to get to work.
Waste & Pollution
  • Affix a decal to recycling container indicating “We Compost.” See the chapter on social diffusion for an example of this sticker.
  • Affix a decal to the recycling container indicating that the household buys recycled products.
  • Ask supermarket shoppers to wear a button or sticker that shows their support for buying products that are recyclable or have recycled content (note that agreeing to wear a button or sticker also increases the likelihood that they will actually shop for these products).
  • Publicly communicate the percentage of people who comply with municipal requests to restrict summer water use.
  • Attach stickers to the sides of recycling containers showcasing that households have reduced either indoor and/or outdoor water use.

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