Setting an example is not the main means of influencing another, it is the only means.

Albert Einstein

Think of the last book that you read, restaurant you ate at, or movie that you watched. What do each of these seemingly unrelated events have in common? All three were likely influenced by friends, family members, or colleagues. More important decisions, such as what neighborhood to live in, what school to send our children to, or who to have as a family doctor, are all similarly influenced.

Both the mundane and important decisions of our lives are strongly affected by a process known as social diffusion or diffusion of innovations.1 In contrast with what nonpersonal sources of information, such as brochures or advertising, conversations that we have with others, and particularly with those whom we trust and perceive as similar to ourselves, have an inordinate influence.2 While social diffusion has been studied and applied extensively in fields such as public health, it has received surprisingly little attention regarding sustainable behavior. This lack of application is striking as many sustainable behaviors, such as carpooling or installing a grassed waterway on a farm, involve adopting a new innovation.3 The relevance of social diffusion to the adoption of sustainable behaviors has been commented on by Aronson and Gonzales. They note that social diffusion can be easily observed by walking through California neighborhoods, where the homes that have installed solar collectors tend to “ . . . ‘cluster’ throughout the neighborhood—reflecting the social networks of residents who purchase and install solar heating devices” (p. 318).4 I’ve witnessed this same process in the Pacific Northwest of the United States, where similar clusters of homes have replaced the grass in their front yard with drought-tolerant plants.

social diffusion and Sustainable Behavior

Below are several examples of sustainable behaviors that have been influenced by social diffusion.

  • During the 1930s, both American and Canadian farmers were losing dramatic amounts of topsoil from their fields. In response to this crisis, the U.S. government distributed brochures which detailed the problem and suggested actions, such as planting trees as wind screens, that could be taken to slow the loss of topsoil. Like the information campaigns discussed in the first chapter, this attempt to influence the behavior of farmers was a dismal failure. When it was clear that farmers were not changing their agricultural practices, the government tried a new approach that involved working directly with a small number of farmers. These farmers received direct assistance in adopting practices that would slow erosion. It was reasoned that farmers might be more apt to adopt new approaches if they were first modelled by a farmer in their area. Modelling a new technique, such as installing wind screens or alternative methods of tillage, it was believed, would be far more compelling than dryly describing the technique in a pamphlet. Further, it would encourage farmers to discuss the new technique and, if they observed that it was working successfully on a local farm, increase the likelihood that they would adopt it themselves. Unlike the campaign that involved distributing brochures, this approach was far more successful. Neighboring farmers observed the changes that the early adopters were making, discussed them with them, and adopted similar practices once they saw the results. As a consequence, these new agricultural practices diffused quickly.5

  • Those who install programmable thermostats have been found to influence the likelihood of friends, family and coworkers installing them, but not their neighbors. This finding suggests the importance of social networks, over geographical proximity, in determining social diffusion.6

  • Those who intend to install solar panels have been found to have friends and colleagues who had already installed them.7

  • In a survey that investigated curbside recycling participation, recycling by friends and neighbors predicted recycling by the respondent.8

Whether a new sustainable behavior, or innovation, is likely to be adopted has been found to depend upon the following factors,which have been found to be highly predictive of social diffusion. 9,10,11,12

  • Relative Advantage: Is the behavior perceived to be clearly superior to the behavior it replaces?

  • Perceived Risk: Will adopting the behavior increase the probability of financial loss or social disapproval?

  • Complexity: Is the new behavior challenging?

  • Compatibility: Is the behavior compatible with the values of the target audience?

  • Trialability: Can the behavior be trialed, before making a long-term commitment?

  • Observability: Is the behavior visible to others?

Using social diffusion effectively

The media often plays an important role in beginning the diffusion process by facilitating the adoption of the new behavior by a small minority of people. Research suggests, however, that once a minority of people have adopted a new sustainable behavior that personal conversations play the pivotal role in the behavior being adopted more broadly.13

Commitments can be combined with social diffusion to influence the rapid adoption of a new behavior. In an important study, residents who had been previously identified as putting their grass clippings at the curbside for disposal, were assigned into two groups.14 The first group was approached and asked to make a commitment to leave their clippings on their lawn. The second was asked to make a commitment to grass cycle and to ask their neighbors to do the same. The “commitment only” request had no effect on grass cycling. However, those who were asked to speak to their neighbors, as well as make a personal commitment to grass cycle, increased not only their own grass cycling, but also that of their neighbors. Importantly, these findings were still observable 12 months later.

Social diffusion is hampered when the behavior to be fostered is invisible. Unlike curbside recycling, in which engagement in the behavior is visible every time someone puts their container at the curbside, composting, like many other sustainable behaviors, occurs out of view. How can composting, and other residential behaviors, be made more visible? Attaching stickers that proclaim “We Compost Too” to the side of the recycling or garbage container can help to create and maintain community visibility for this behavior.

Whenever possible, seek commitments that are both public and durable. The sticker below was used in a program to encourage backyard composting in Nova Scotia, Canada. Households were called and asked if they composted. If they did, they were asked to place the sticker on their curbside recycling container. Placing stickers, such as the one below, on a curbside container has several positive benefits. First, each time the recycling container is taken to the curb it profiles that the household is engaged in backyard composting. Due to the importance of behaving consistently, which was discussed in the chapter on commitment, the likelihood that the household will continue to engage in composting has been increased. Second, a behavior that would otherwise be invisible in the community has been made visible. By making the behavior visible, we increase the likelihood of fostering both social diffusion and descriptive social norms. Behaviors that remain invisible will diffuse slowly and are unlikely to become normative.

© Valley Region, Nova Scotia, Canada

Here are some guidelines for using these stickers:

  1. Lamination: Use a heavily laminated sticker with good adhesive so that the sticker will last for several years.
  2. Permission: Ask the household for permission to place the sticker on their recycling container as compared to asking them to place the sticker on themselves. While engagement in an activity has been found to enhance commitment, asking for permission dramatically increases the number of stickers that show up in a community. In a project that I worked on in California, over 80% agreed to place stickers on their recycling containers, but only 26% did. In contrast, when permission to place stickers on containers was obtained, and households were simply asked to place their recycling containers at the curbside in a community in Massachusetts, the number of stickers that were affixed more than doubled.
  3. Visibility: Ensure that the sticker and the text on it is visible from a distance. To ensure visibility, the sticker on the opposite page was the size of a car bumper sticker.

A Checklist for Using social diffusion

Follow these guidelines in implementing social diffusion in your programs.

  • As just noted, ensure that the behavior you are promoting is visible.
  • Gain commitments from early adopters to speak to others about the behavior.
  • Carefully identify who to target. For example, geographic infor-mation systems (GIS) are now being used along with satellite imagery to determine not only vulnerable areas of a watershed, but also what actions have already been taken by landowners. Because these systems are able to detect geographic features, such as grassed waterways, they can be used to identify early adopters who might be targeted as part of a campaign to foster social diffusion. Ben Tyson and his colleagues are already supplementing GIS systems with information regarding landowners receptivity to engaging in best management practices.16

Below are a variety of examples of how social diffusion can be used to foster sustainable behavior.

Examples: Using Social Diffusion to Foster Sustainable Behavior
Agriculture & Conservation
  • Use booklets, such as the one described in the case study in this chapter, to foster the adoption of best management practices.
  • Residential energy efficiency actions are for the most part invisible to other residents. Increase their visibility by obtaining public and durable commitments that showcase these actions. One such program in Canada involves residents having their photos taken while holding a pledge board in front of them. These photos are then displayed in public settings and on the internet.
  • Bear Creek Elementary School in Boulder, Colorado encouraged children to walk or bike to school. One component of this program includes children being given different colored arm bands based on the distance they have travelled to school via biking and walking. The arm bands generate conversations amongst the children about walking and biking to school.
Waste & Pollution
  • Encourage the use of reusable water containers or the picking up of litter at children’s recreation centers by having teams have their photos taken and placed under a display committing to bring reusable water containers and/or to pick up litter. The display serves as a reminder of their commitment, and enhances social diffusion.
  • Ask households if a sticker can be placed on their curbside recycling container showcasing that their household reduces indoor and outdoor water use.

Next Chapter » Prompts: Remembering to Act