Although much research has focused on the most sustainable, environmentally-friendly strategies to address various issues, an important piece of the puzzle is often ignored: Now that we know the best course of action, how do we get people to engage in the proposed sustainable behaviors?
To answer the question of what influences an individual’s behavior, we can turn to the theory of planned behavior, a popular social-psychological model. According to the theory of planned behavior, a person’s intention predicts if they will actually perform a behavior. Intention is influenced by a person’s attitude, subjective norm, and perceived behavioral control.
It is important to note that the theory of planned behavior, though one of the most commonly applied theories, is not the only theory in social science that can be used to understand human behavior. In this article, I focus on this theory in order to highlight the benefits of integrating social science into sustainability research.
Breaking Down the Theory of Planned Behavior
Attitude is a measure of how favorably a person views a behavior. It is influenced by the person’s beliefs about the behavior itself and the outcome of the behavior. For example, a person could feel negatively about using plastic products instead of reusable options, while also feeling positively about the outcome of this behavior (i.e. convenience, less expensive in the short term). To account for these two dimensions, social scientists employing the theory of planned behavior typically ask study participants to use a scale (i.e. a six-point scale where one represents strong disagreement and six represents strong agreement) to rate a statement about a particular behavior, followed by a statement about the outcome of that behavior. Afterwards, scientists multiply the two ratings to get an overall score for the respondent’s attitude. The higher the score, the more positively the respondent feels about the behavior in question (i.e. using plastic products).
Subjective norms are the behaviors considered normal by a group that the individual values. A person’s beliefs about what is normal for others in the group (i.e. do others in your social group recycle?) and how important it is to comply with that norm (i.e. is it important to you to behave the way that others in your group expect?) influence their subjective norm. These norms are based on what the respondent thinks others in their social group think or do, rather than on the actual behavior of others in the group.
The last aspect of the theory of planned behavior is perceived behavioral control. This dimension addresses how much power a person feels they have in performing a behavior (i.e. is it easy for your household to recycle?).
Using the Theory of Planned Behavior to Predict Sustainable Behaviors
Knowing a person’s attitude, subjective norms, and perceived control gives scientists an insight into why people behave as they do. Scientists who use the theory of planned behavior can typically predict between 50-70% of the variation in a particular behavior.
Different behaviors vary in what attributes are most predictive. For example, boaters in Florida are motivated to follow boating speed limits in areas with manatees because of subjective norms and a desire to comply with law enforcement. On the other hand, farmers in Pakistan, where farm forestry has been proposed to counteract the loss of forested land, were more likely to comply if they held favorable views of the advantages of planting trees on their land.
How the Theory of Planned Behavior Can Aid Efforts to Promote Sustainable Behaviors
Understanding why people engage in a particular behavior enables us to design more effective methods of intervention. Sustainability research studies are beginning to include social-psychological perspectives and apply the knowledge gained to create more effective interventions.
A recently published study of restaurant managers used the theory of planned behavior and institutional theory, which predicts how an organization will behave, to investigate what motivates managers to adopt sustainable restaurant practices. They found that managers were most influenced by what their suppliers and customers expected.
Another recent study found that the recycling behavior of ethnic minorities in Ontario, Canada was best predicted by their perceived behavioral control, attitudes, and moral norms (a specific type of subjective norm). This information was used to develop an educational program that promoted the community’s recycling program. The program was given by the leaders of 12 religious institutions in the community. When community leaders who were important to the target audience delivered the message, the intervention was more successful in positively changing intentions to recycle, compared to previous efforts by municipal leaders who weren’t as important to the target audience.
Studies that account for human behavior without directly applying the theory of planned behavior have also had success changing behavior. At Western Colorado State University, a team of researchers observed four buildings with existing recycling programs. They then made changes to the locations of waste and recycling containers based on their observations. They saw an improvement in in the amount of recyclable materials deposited in the correct receptacle in every location monitored after making changes that “nudged” students to recycle properly.
The success of Western Colorado State University’s intervention demonstrates the utility of acknowledging and accounting for human behavior, even without a theoretical framework. Anyone, even if not a researcher or community leader, can use the general ideas of the theory of planned behavior to have more productive conversations about sustainability. The key is to find out what motivates the target audience, whether that’s a friend, coworkers, or a larger group. Then, the message must be tailored to address that motivation.
The body of research related to sustainability continues to grow and deepen our knowledge of best practices. The field would further benefit from a consideration of what motivates different groups of people to adopt best practices. The growing integration of the theory of planned behavior and sustainability studies is one example of what this collaboration might look like, as the field of sustainability moves forward.
Image courtesy of Flickr. Originally published by S&S on December 13, 2018.