Yale Program on Climate Change Communication

We are pleased to announce the publication of a new article, “Testing the durability of persuasion from moral appeals about renewable energy” in the journal Science Communication. This project was conducted in collaboration with the Center for Public Engagement with Science at the University of Cincinnati. This study examines the persuasive effects of moral appeals on public support for the transition from fossil fuels to clean, renewable energy.

The global transition from fossil fuels to renewable energy sources (such as solar and wind) will be greatly affected by social factors such as public opinion, consumer demand, and political support. Political polarization over renewable energy has increased in the U.S. over the past five years. This divisive political climate underscores the importance of finding ways to communicate about renewable energy across different segments of the public.

Here, we report findings from a recent experiment investigating whether persuasive effects are enhanced by explicitly emphasizing the moral and ethical aspects of different energy sources. Overall, we found that messages describing the negative effects of fossil fuels and advantages of clean energy had strong and durable effects and nothing was gained by adding an explicit claim about ethics. While this is only one study, the findings suggest that direct statements about the morality or immorality of different energy sources do not necessarily enhance the persuasiveness of messages. 

Research participants were randomly assigned to watch one of five animated videos. Two non-moralized videos explained how fossil fuels can harm human health and the environment, respectively. Two “moralized” videos contained the same information but also included additional arguments about why this means using fossil fuels is inherently immoral, because doing so harms innocent people or contaminates the purity of nature, respectively. The image below provides an example. The fifth video, which provided information about an unrelated topic, was used as the control (baseline) condition.

We found that all four messages were effective at changing beliefs about renewable energy and support for an energy transition. However, adding the specific moral claims (e.g., “this is unethical”) did not increase the persuasiveness of the message. Instead, all messages were similarly effective.

Persuasive Effects Over Time

In addition to investigating the immediate persuasive effects of the messages, we also tested how long the persuasive effects lasted. Most studies on persuasion only measure immediate effects – that is, how attitudes and opinions are affected right after persuasive messages are presented. But it is critical to also understand how durable these changes are. Persuasion that quickly fades away might not be practically useful, especially when the desired outcomes are longer-term, such as changing daily habits or voting in a future election.

Accordingly, we measured participants’ opinions at three different times: immediately after seeing the message, about 10-12 days later, and then finally after another 10-12 days. This allows us to measure how much the initial changes in opinions persisted (or decayed) over time. Our findings (visualized in the figure below) showed that all four messages – whether moralized or not – had durable persuasive effects on people’s support for a transition to renewable energy. Across the four different messages, about 30-50% of the original treatment effect was still present after about three weeks. However, we found no evidence of an added boost in durability from the explicit moralization of the message. Instead, there was similarly strong durability across all versions of the message.

The full article with many other results is available here to those with a subscription to Science Communication. If you would like to request a copy of the published paper, please send an email to climatechange@yale.edu with the subject line: Request Moral Messaging Durability paper. Or, a public version is available here.