Our deeds determine us as much as we determine our deeds.

George Elliot

Imagine being asked to place a large, ugly, obtrusive billboard with the wording “DRIVE CAREFULLY” on your front lawn. When a researcher, posing as a volunteer, made precisely this request, numerous residents in a Californian neighborhood flatly declined.1 That they declined is hardly surprising, especially since they were shown a picture of the billboard almost completely obscuring the view of another house. What is surprising, however, is that fully 76% of another group of residents in this study agreed to have the sign placed on their lawn. Why would over three-fourths of one group agree, while virtually everyone in the other group sensibly declined? The answer lies in something that happened to the second group prior to this outlandish request being made. The residents who agreed in droves to have this aberration placed on their lawn were previously asked if they would display in the windows of their cars or homes a small, three inch sign that said, “be a safe driver.” This request was so innocuous that virtually everyone agreed to it. Agreeing to this trivial request, however, greatly increased the likelihood that they would subsequently consent to having the billboard placed on their lawn.

Are these findings a mere anomaly? Apparently not. In another study, a researcher, identifying himself as a member of a consumer group, called and asked householders if he could ask them a few questions about their soap preferences.2 A few days later the same researcher called back asking for a much larger favor, “Could I send five or six people through your house to obtain an inventory of all the products in the house?” The caller carefully explained that this “inventory” would require searching through all of their drawers and closets, etc. Having agreed to the smaller request only a few days earlier, many of the householders apparently felt compelled to agree with this much larger and more invasive request. Indeed, over 50% agreed, more than twice as many relative to householders who had not received the prior request. These surprising findings have now been replicated in a variety of settings. In each case, individuals who agreed to a small initial request were far more likely to agree to a subsequent larger request. For example:

  • When asked if they would financially support a recreational facility for the handicapped, 92% made a donation if they had previously signed a petition in favor of the facility, compared with 53% for those who had not been asked to sign the petition.3

  • Residents of Bloomington, Indiana, were called and asked if they would consider, hypothetically, spending three hours working as a volunteer collecting money for the American Cancer Society. When these individuals were called back three days later by a different individual, they were far more likely to volunteer than another group of residents who had not been asked the initial question (31% versus 4%, respectively).4

  • A sample of registered voters were approached one day prior to a U.S. presidential election and asked, “Do you expect you will vote or not?” All agreed that they would vote. Compared to voters who were not asked this simple question, their likelihood of voting increased by 41%.5

  • Ending a blood-drive telephone call with the query, “We’ll count on seeing you then, OK?” increased the likelihood of individuals showing up from 62% to 81%.6

  • Individuals who were asked to wear a lapel pin publicizing the Canadian Cancer Society were nearly twice as likely to subsequently donate than were those who were not asked to wear the pin.7

  • When residents of a college community were asked to sign promise cards to use crosswalks and yield to pedestrians in crosswalks when driving, crosswalk usage increased by 10% and yielding to pedestrians in crosswalks increased by 21%.8

Understanding Commitment

Why does agreeing to a small request lead people to agree subsequently to a much larger one? When individuals agree to a small request, it often alters the way they perceive themselves. That is, when they sign a petition favoring the building of a new facility for the handicapped, the act of signing subtly alters their attitudes on the topic.9,10 Through a process that Darryl Bem refers to as self-perception they come to view themselves as the type of person who supports initiatives for the handicapped.11 When asked later to comply with the larger request, giving a donation, there is strong internal pressure to behave “consistently.” Similarly, saying that you “think” you would volunteer for the Cancer Society, vote in an election, give blood or wear a lapel pin, alters your attitudes and increases the likelihood that you will later act in a way that is consistent with your new attitudes.

Consistency is an important character trait.12 Those who behave inconsistently are often perceived as untrustworthy and unreliable. In contrast, individuals whose deeds match their words are viewed as being honest and having integrity. The need in all of us to behave consistently is underscored by an intriguing study on a New York City beach. In this study, a researcher posing as a sunbather put a blanket down some five feet from a randomly selected sunbather. He then proceeded to relax on the blanket for a few minutes while listening to his radio. When he got up he said to the person beside him, “Excuse me, I’m here alone and have no matches ... do you have a light?” He then went for a walk on the beach, leaving the blanket and radio behind. Shortly afterwards, another researcher, posing as a thief, stole the radio and fled down the beach. Under these circumstances, the thief was pursued 4 times out of 20 stagings. However, the results were dramatically different when the researcher made a modest request prior to taking the walk. When he asked the person beside him to “watch his things,” in 19 out of the 20 stagings the individual leapt up to pursue the thief. When they caught him some restrained him, others grabbed the radio back, while yet others demanded an explanation. Almost all acted consistently with what they had said they would do.13

The need to behave consistently is further supported by findings that a substantial amount of time can pass between the first and second request, and that the second request can be made by a different individual. That considerable time can pass between the two requests provides further evidence that complying with the initial request alters the way we see ourselves in an enduring way. Furthermore, that we will comply with a second request initiated by a new person, indicates that these changes are not transitory; otherwise we would only feel bound to comply if the second request were made by the same individual who had made the initial request.

Commitment and Sustainable Behavior

As detailed above, commitment techniques have been shown to be effective in promoting a diverse variety of behaviors. This behavior change tool has also been shown to be effective in promoting sustainable behavior. Here are several examples:

  • In research carried out with Pacific Gas and Electric, home assessors were trained to make use of commitment strategies as well as other behavior change tools.14 The assessors were trained to secure a verbal commitment from the householder. For example, the householder might be asked, “When do you think that you’ll have the weather-stripping completed? ... I’ll give you a call around then, just to see how it’s coming along, and to see if you’re having any problems.” These subtle changes in how the assessment was presented resulted in substantial increases in the likelihood that householders would retrofit their homes. In fact, using these behavior change tools resulted in three to four times as many people electing to retrofit their homes.

  • Commitment techniques have also been applied in the retail sector. In this study, small retail firms were randomly assigned to either a “mild commitment,” “strong commitment” or “control” condition.15 In the “mild commitment” condition, the names of the firms were published every other month along with information about the energy conservation initiative. In the “strong commitment” condition not only the names of the firms were published, but also the extent to which they had, or had not, saved energy. In all three cases, companies received information on steps they could take to reduce energy use and received a free energy audit. While the three groups did not differ in the amount of electricity they consumed, the two commitment conditions used significantly less natural gas than did the control group. Importantly, firms in the “mild commitment” condition used less natural gas than firms in the “strong commitment” condition. Informal comments from the owners of the companies in the “strong commitment” condition suggest that they felt trapped by the public disclosure of their initial lack of success in saving energy and that they subsequently stopped attempting to save energy. It is important to note that, in this study, there was no explicit commitment pledge. The researchers assumed that having their names publicly displayed would enhance commitment, but they did not directly ask for a commitment.

  • Commitment has also been used to promote bus ridership. Individuals who did not ride the bus were assigned to one of four conditions. In the “information only” condition, participants received route and schedule information as well as identification cards that allowed ridership to be monitored. In the “commitment condition,” participants made a verbal pledge to ride the bus twice a week for four weeks, while in the “incentive condition,” participants were given ten free bus tickets and were informed that they could receive more tickets when they had used the initial tickets. Finally, in the “combined condition,” participants both made a pledge to ride twice a week for four weeks and received free tickets. Each of the three conditions increased bus ridership. However, it was found that participants in the “commitment only” condition rode the bus just as frequently as the participants in the “incentive condition” and the “combined condition.” Importantly, these effects were observable during two follow-ups, conducted at three and twelve weeks after the intervention.

  • In a unique study, homeowners were mailed either a shower flow restrictor along with a pamphlet on energy conservation or just the pamphlet alone.19 Homes that received the shower flow restrictor in addition to the pamphlet were not only more likely to install the restrictor, an obvious finding, but were also more likely to engage in the other conservation actions mentioned in the pamphlet, for example, lowering the temperature on their water heaters, installing setback thermostats or cleaning their furnaces. Apparently, having installed the shower flow restrictor altered how these individuals perceived themselves. In short, they came to see themselves as the type of individuals who are concerned about energy conservation and, as a result, carried through with the other actions suggested in the pamphlet.

  • Obtaining a signed commitment increased curbside recycling in Salt Lake City, Utah, more than receiving a flyer, a telephone call or personal contact alone.20

  • Farmers in the Netherlands who received farm-specific information on the actions they could take to protect their local watershed and enhance biodiversity, and subsequently committed publicly to engage in these actions at a meeting, were more likely to alter their behavior than were farmers who received only farm-specific information.21

Using Commitments effectively

A variety of studies have clarified when commitments are likely to be most effective. Written commitments appear to be more effective than verbal commitments.22 In a study that investigated the impact of verbal versus written commitments, households were assigned to one of three groups. In the first group, homes simply received a pamphlet underscoring the importance of recycling newspaper. In the second group, households made a verbal pledge to recycle newsprint. In the third group, households signed a statement in which they committed themselves to recycle newsprint. Initially, the households that made either a verbal or written commitment recycled more newsprint than households that received only a pamphlet. However, only the households that committed themselves by signing the statement were still recycling when a follow-up was conducted.

Whenever possible, ask permission to make a commitment public. The dramatic impact that public commitments can have is illustrated in a study in which either a private commitment to conserve electricity and natural gas was obtained, or a public commitment was obtained, in which names would be published in the local newspaper.

Those who agreed to a public commitment saved significantly more energy than did householders who were in the private condition. Even after the researchers informed the participants who had agreed to a public commitment that their names would not be published, they continued to save energy. While the names were never publicized, simply asking for this permission brought about a 15% reduction in natural gas used and a 20% reduction in electricity used. Importantly, these reductions were still observable 12 months later.23 Public commitments are likely so effective because of our desire to be consistent. In short, the more public a commitment, the more likely we are to honor it.

Seeking commitments in groups can also be effective. When the economic and environmental benefits of recycling were explained to members of a retirement home, and they were asked to make a group commitment, there was a 47% increase in the amount of paper recycled.24 The authors suggest that group commitments are likely to be effective in settings where there is good group cohesion. This suggests group commitments are likely to be effective in well-established groups in which individuals care how they are viewed by other members of the group.

Commitment can be increased not only by seeking a verbal or written pledge, but also by actively involving the person. In the Pacific Gas and Electric study mentioned above, home assessors were trained to involve the home owner actively in the assessment.25 Home owners were asked, for example, to peer into their attic to inspect the insulation level or to place their hand on an uninsulated water heater, etc. After being involved in this way, home owners are more likely to see themselves as committed to energy conservation.

Commitment strategies have been criticized as too labor-intensive to warrant implementation on a broad scale.26 However, implementing commitment as part of a home visit, as was done in the Pacific Gas and Electric study, is a viable option. Furthermore, asking for a commitment when a service is provided, such as delivery of a compost unit or a water efficiency kit, is a natural opportunity to employ this strategy. Two other strategies are worth considering in making use of commitment. First, existing volunteer groups can be used. In one study, Boy Scouts asked residents to sign a statement agreeing to participate in a community recycling program. Those households who were asked to sign the statement were much more likely to participate than was a control group who was not asked (42% and 11%, respectively).27

Second, commitment strategies have also been shown to be effective when community “block leaders” implement them. A block leader is a community resident who already engages in the behavior that is being promoted and who agrees to speak to other people in their immediate community to help them get started. In this study, block leaders approached homes and used a variety of community-based social marketing strategies, including seeking a verbal commitment, to encourage the household to begin recycling. The homes that were visited by a block leader were more than twice as likely to recycle than was a group who received flyers.28

Commitments should be sought only for behaviors which people express interest in doing. Hence, if a block leader approaches a home and asks if the residents are interested in composting, commitment should only be sought if the household expresses an interest in the activity. Indeed, research suggests that commitment will not work if the person feels pressured to commit. In order for commitment to be effective, the commitment must be voluntary.

Earlier in this chapter I suggested that one of the reasons for the dramatic impact of small requests upon subsequent behavior was that responding to a small request alters how we see ourselves. If how we see ourselves is an important predictor of how we will act in the future, it makes sense that programs to promote sustainable behavior should actively assist people to see themselves as environmentally concerned. Support for this assertion comes from a study that investigated the impact of assisting people to see themselves as charitable.29 In this study, householders were approached and asked if they would make a donation to the Heart Association. Half of the individuals who volunteered to make a donation were thanked and told, “You are a generous person. I wish more of the people I met were as charitable as you,” while the other half were simply thanked. One to two weeks later these same individuals were approached by another individual and asked if they would donate money to multiple sclerosis. Not only did more of the “generously labeled” people give money to multiple sclerosis, they also gave morefully 75% more. This research suggests that when possible we should be helping people to see themselves as environmentally concerned. For example, when encouraging someone to try a new activity, such as carpooling, we should begin by pointing out the other positive sustainable behaviors that they are already involved in.

A Checklist for Using Commitment

When considering using commitment, check that the following guidelines have been followed:

  • Emphasize written over verbal commitments
  • Ask for public commitments
  • Seek group commitments
  • Actively involve the person
  • Consider cost-effective ways to obtain commitments
  • Use existing points of contact to obtain commitments
  • Help people to view themselves as environmentally concerned
  • Don’t use coercion (commitments must be freely volunteered)
  • Combine commitment with other behavior change techniques
Examples: Using Commitment to Foster Sustainable Behavior
Agriculture & Conservation
  • As noted in this chapter, ask farmers to commit publicly at a meeting to engage in actions related to watershed and biodiversity protection.
  • Protect nesting shore birds by asking beachgoers to keep dogs on a leash and to stay away from marked nesting areas. Make their commitments public and durable by requesting their picture be taken. Post the photos in displays along the boardwalks that lead to the beach. Posting the photos along these walkways serves as an ongoing reminder to these individuals of the commitment they have made each time they pass the display. Furthermore, the display serves as way of fostering social norms and social diffusion. (See the chapters on norms and social diffusion for more information.)
  • As mentioned previously in this chapter, when conducting a home assessment, invite the home owners to participate.
  • Conclude a home assessment visit by asking the home owners when they expect to complete activities such as weather-stripping or installing a programmable thermostat. Ask for permission to call back to help home owners troubleshoot any problems they had with installation. There is a high likelihood that they will engage in the action in anticipation of the call back.
  • Ask commuters to sign a public commitment that they will take mass transit once or twice a week for a specific period of time. (See the study on bus ridership in this chapter.)
  • Ask vehicle owners to commit to turn their car off while waiting to pick someone up. Provide a prompt that they can affix to their windshield or dashboard to remind them to turn their engine off. (See the case study in this chapter for further information.)
  • Ask car owners to commit publicly to checking their car’s tire pressure once a month. Provide prompts at gas stations reminding people to check their tire pressure. Have gas attendants also commit to reminding people to check their tire pressure.
Waste & Pollution
  • When distributing compost units, ask when the person expects to begin to use the unit and inquire if you can call shortly afterwards to see if he/she is having any difficulties.
  • Ask households who have just received a compost unit to place a sticker on the side of their recycling container indicating that they also compost.
  • Ask people entering grocery stores to wear a button or sticker supporting the purchase of products that have recycled content or are recyclable. (See also the chapter on social norms.)
  • In retail outlets, place decals on household hazardous waste containers that provide information on where HHW can be taken for proper disposal. Partner with retail outlets to have customers sign the decal and commit themselves to taking unused amounts of the product to the depot for proper disposal.
  • Ask homeowners to make a commitment to raise the height of their lawn mower, thereby reducing evaporation and the need for lawn watering.

Next Chapter » Social Norms: Building Community Support