Although the government has implemented waste separation policies to promote the participation rate of waste separation, residents’ actual waste sorting behavior remains low. The growth of waste has become a critical global issue because it poses a threat to human health and causes environmental pollution. Given the urgency of waste disposal problems, it is essential to explore how to promote individuals’ waste sorting behavior.
According to the deterrence theory, individuals make rational decisions through a cost-benefit balance. An effective environmental regulation system plays a crucial role in the improvement of waste source separation. However, it is unclear whether mandatory or voluntary is more suitable to encourage residents’ waste sorting behavior.
The self-enhancement bias may influence individuals’ waste sorting behavior. Self-enhancement denotes a class of psychological phenomena that involve taking a tendentiously positive view of oneself. People tend to believe that they are better than others in many favorable characteristics. Waste separation requires cooperation with oneself and others. It is uncertain how people perceive themselves and others in terms of policies and behaviors of waste source separation.
In order to address these unclear issues, Prof. Buxin HAN, Dr. Pingping LIU and collaborators from CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences conducted three studies to explore the effectiveness of mandatory policies and self-enhancement bias for both adults (residents) and adolescents.
Figure 1. Research framework. Image by TANG Jie.
Three studies indicate two key findings. First, the mandatory policy increases the likelihood of waste separation behavior (see Figure 2). Compared to the voluntary policy, people facilitated their willingness to engage in waste separation under the mandatory policy.
Figure 2. Willingness to engage in waste separation behavior perceived by self and others for two policy conditions applied in Study 1. Image by TANG Jie.
Second, there is a robust self-enhancement bias in the waste separation domain. Specifically, both adolescents and adults perceived themselves to be better than others in both their willingness and attitude toward waste separation behavior (see Figure 3). Moreover, participants consider their willingness to engage in waste separation behavior would be similar under the voluntary policy and mandatory policy conditions. However, participants reported that others’ willingness to separate waste would be promoted by a mandatory policy rather than by a voluntary policy.
Figure 3. Attitudes toward waste separation for the self and others conditions for Studies 1 and 2. Image by TANG Jie.
The present research provides empirical evidence for the effectiveness of a mandatory policy in waste separation management. We also observed robust self-enhancement bias in waste separation and extended this bias to the pro-environment field. Our studies provide suggestions for policymakers to improve the effectiveness of policies. It is necessary to increase waste separation participation by recruiting volunteers and clarifying management responsibilities. To implement a mandatory policy is necessary to ensure the long-term effectiveness of waste separation.
This work was published in the Sustainability on 30 November 2021, and partly funded by the Scientific Foundation of Institute of Psychology, Chinese Academy of Sciences , the joint program of Chinese Academy of Sciences and Japan Society for the Promotion of Science , and the National Natural Science Foundation of China .
Zhao, Y#., Chen, R#., Yabe, M., Han, B., & Liu, P*. (2021). I am better than others: Waste management policies and self-enhancement bias. Sustainability, 13, 13257.
Institute of Psychology
Chinese Academy of Sciences
Beijing 100101, China.