Shaping Pro-Environment Behaviors

What works better: Keep Off the Grass or Save the Planet? Psychologists are discovering the types of words and messages that encourage environmentally friendly behaviors. Field research - whether in hotels or literally in the field - are helping everyone from the U.S. Forest Service to conservation-minded businesses to safeguard natural resources more effectively.

Applying theories from social psychology to environmental problems, researchers at Arizona State University tested the power of social norms in influencing behavior. Robert Cialdini, PhD, and two graduate students worked with a local hotel on a program to encourage lodgers to reuse wet towels. The researchers randomly assigned cards with one of five different messages to 260 guest rooms, each with one of the following messages:

• "Help the hotel save energy"

• "Help save the environment"

• "Partner with us to help save the environment"

• "Help save resources for future generations"

• "Join your fellow citizens in helping to save the environment"

The last message, which described a social norm, was the most successful: Forty-one percent of the guests who got those cards recycled their towels. Next best were the messages urging environmental protection and the benefit to future generations, which led to about 31 percent reusing towels. Least successful: The message emphasizing the benefit to the hotel. Only one in five guests with that card reused their towels.

Researchers have found a second type of effective message suitable for other situations. Patricia Winter, PhD, a research social scientist with the Wildland Recreation and Urban Culture Research Unit at the USDA Forest Service's Pacific Southwest Research Station in Riverside, Calif., has tested variations on the tried-and-true "Keep Off the Grass" motif and found them to be effective. These injunctive-proscriptive messages tell people directly what not to do.

Winter evaluated various signs that encourage visitors to stay on established trails in California's Sequoia and Kings Canyon National Parks. Signs stating "Please don't go off the established paths and trails in order to protect the Sequoias and natural vegetation in this park" were the most effective: Only five percent of hikers went off the trail.

However, when signs said, "Many past visitors have gone off the established paths, changing the natural state of the Sequoias and vegetation in this park" some 18.7 people went off the path. Without any signs, 30.9 percent strayed. In this case, describing a negative social norm didn't work as well as issuing a direct request.

Cialdini found similar results: In the Petrified Forest National Park in Arizona, he found that fewer people stole petrified wood from the park when signs indicated the appropriate behavior, in this case, not doing something: "Please don't remove the petrified wood from the park, in order to preserve the natural state of the Petrified Forest."

Cialdini's colleagues found their hotel results consistent with the social psychological theory that when people are figuring out what to do in a new situation, they take their cue from what seems to be other people's normal behavior - the social norm. Thus, descriptive norm messages that say, "Everybody's doing it!" to promote conservation-minded actions may be most effective.

Meanwhile, in situations requiring people not to do something, injunctive-proscriptive messages ("Don't go off the trail" and "Don't take the wood") seem to work. In fact, Winter found that an injunctive-proscriptive message was twice as effective in deterring off-trail hiking as a descriptive-prescriptive message ("Stay on the trail.") Given this evidence, she believes that in this situation, saying "Don't do this" is the most direct route to gaining compliance.

Psychologists are finding that even slight variations in wording can shape behavior powerfully, making it important to write the right kind of message on the right kinds of signs. Given the urgency of conserving natural resources, including energy, this research can help all interested parties, public and private, to more effectively encourage pro-environmental behaviors.

Significantly, not only are certain messages more effective, but some can actually backfire. The studies showed that descriptive-proscriptive messages, which describe undesirable actions as the norm, have unintended power. If signs are going to describe the actions of others, they should present only positive behaviors as the norm.

Winter and psychologist Shawn Burn, PhD, of California Polytechnic State University in San Luis Obispo have developed a handbook to help environmental managers in local government, national parks and the like to develop scientifically sound pro-environment interventions. The handbook encourages resource managers and community leaders to apply social-science findings to remove barriers to pro-environmental behavior and to develop interventions that promote those behaviors, including carefully designed persuasive messages. Similarly, Canadian environmental psychologist Doug McKenzie-Mohr, PhD, delivers workshops and training to communities to explain community-based social marketing strategies.

The research also implies that the typical "save the planet" awareness campaigns aren't useful for shaping specific behaviors due to their lack of specificity. Research into effective persuasion, Winter explains, has shown that specific messages - the right specific messages -- are much more likely than abstract messages to shape behavior. By adapting new insight into the power of social norms for doing the right thing, and the strength of negative injunctions for not doing the wrong thing, environmental interests can promote essential behaviors in a more effective way.

Cialdini, R. B. (2003). Crafting normative messages to protect the environment. Current Directions in Psychological Science, 12, 105-109.

Cialdini, R. B., Barrett, D. W., Bator, R., Demaine, L., Sagarin, B. J., Rhoads, K. v. L., & Winter, P. L. (in press). Activating and aligning social norms for persuasive impact. Social Influence. [As of October 2005]

Goldstein, N. J., Cialdini, R. B., & Griskevicius, V. (2005). A room with a viewpoint: Using norm-based appeals to motivate conservation behaviors in a hotel setting. Manuscript submitted for publication. [As of October 2005].

Winter, P.L., Sagarin, B.J., Rhoads, K., Barrett, D.W., Cialdini, R.B. (2000). Choosing to encourage or discourage: Perceived effectiveness of prescriptive and proscriptive messages. Environmental Management, 2(6): 588-594.

American Psychological Association, October 20, 2005