Metaphors in Persuasive Communications
By Paul H. Thibodeau & Stephen J. Flusberg
The art and science of persuasion has ancient roots. According to Aristotle, persuasive communications involve three factors that move an audience: logos (the rational logic behind an argument), pathos (the emotional resonance of a message) and ethos (the perceived character of the speaker). Modern psychology has largely vindicated Aristotle’s formulation while integrating it within a contemporary scientific framework.
Psychologists have found that there are two routes to persuasion (Petty & Cacioppo, 1986). One, sometimes called the “central route,” explains how attitudes and beliefs can change as a result of rational deliberation (building on the idea of logos). For example, a person’s attitudes and beliefs about climate change may shift to be more consistent with the scientific consensus as a result of carefully considering the scientific evidence on the issue. The other way that attitude change happens is through the “peripheral route,” as a result of factors unrelated to the quality of an argument, like an emotional reaction to the message or messenger (building on the ideas of pathos and ethos). For example, a person’s attitudes and beliefs about climate change may shift to be more consistent with the scientific consensus because they get scared hearing about a recent wildfire disaster or information is shared by a trusted friend, neighbor or colleague.
Persuasion occurs through the rational route when people are motivated and able to evaluate a message. This is what we normally think of as deliberate, rational reasoning. In contrast, persuasion happens through the peripheral route via heuristic processes — fast, automatic “mental shortcuts” like simple associations and emotional reactions, which people rely on when they lack the motivation or ability to carefully evaluate a message.
Aristotle argued that metaphors are useful rhetorical tools, an assertion modern scientific research backs up. In the following sections, we describe how metaphors can enhance persuasion along both the central and peripheral routes, connecting these findings to some of the ideas we have discussed in previous essays in this series. We conclude with a set of practical take-aways for those wishing to use metaphors to enhance their own persuasive appeals.
- Metaphor and rational thinking
The central or rational deliberation route to persuasion involves convincing people of the logic of an argument and getting them to meaningfully evaluate the content of a message. This leads to more stable attitude changes than persuasion via the emotional route alone. Metaphors can help in two ways.
First, metaphors can help spark interest in the subject. A widely read article on the New York Times website was about housing policy. While housing policy is incredibly important, its relevance took on greater meaning during the pandemic when people were being asked to mostly stay in their homes. But as an issue, it can appear to be dull. However, to boost the article’s appeal, the Times headlined it with an evocative metaphor: “An ‘Avalanche of Evictions’ could be Bearing Down on America’s Renters” (link). The imagery and emotions evoked by the headline help make people care enough to read about the rent crisis with my deliberation.
Brain research has found that metaphoric language is more emotionally engaging than literal language (Citron & Goldberg, 2014). Even conventional metaphoric expressions like “She looked at him sweetly” — compared to literal paraphrases like “She looked at him kindly” — have been found to enhance the part of the brain associated with processing emotions. We’re much less likely to meaningfully evaluate a persuasive message if we have little to no interest in the topic at hand, and metaphors can help motivate people to care.
Metaphors can enhance persuasion via the central route by increasing understanding of topics by connecting to other issues. Statements like “Racism is a virus,” “Cancer is a journey,” and “Ideas are light bulbs” prompt people to draw connections between their knowledge of viruses, wars, journeys, and light bulbs and their knowledge of racism, climate change, cancer, and ideas. For example, ideas are similar to light bulbs because both can be speedy, effortless, and transformative (illuminating).
Second, metaphors can also support arguments by connecting people to familiar experiences (Sopory & Dillard, 2002). For example, an important exception to the negative framing of immigration and the refugee experience is to frame their process as a journey or cultivation (Catalano, 2016). Catalano argues that by connecting this experience through the framing of “life as a journey” or as an indication of transformative power and personal metamorphosis, others can connect to this experience. Similar to any physical journey one may undertake with twists and setbacks to overcome, the humanitarian community can frame movement and change as something that has always been and always existed within the human and more-than-human species on Earth.
At the UN Refugee Agency (UNHCR), humanitarians often highlight how people are transformed through the experience of being displaced — both positively and negatively. In some circumstances and stories, this cultivation and change can manifest itself through new understandings of creativity, ingenuity and desire within displaced communities. This is exemplified in the story from UNHCR’s Innovation Service titled, Why community-led innovation is fuelled by risk, ambition, and experimentation, which highlights the transformation that Peter Batali, Co-Founder and Executive Director of Community Technology Empowerment Network (CTEN), underwent as he was forcibly displaced from his home in South Sudan. Through understanding his experience as a journey and the metaphor of transformative power, people can understand that putting refugees at the forefront of developing creative solutions, and that they too can connect to these stories through journeys of their own.
2. Metaphor and the peripheral route
The emotional route to persuasion involves shaping people’s attitudes and beliefs without having them think through the logic of your argument. Instead, the goal is to activate more automatic — and less rational — thinking that psychologists have found influence decision-making.
While emotional engagement can spark a deeper dive into an issue, people often rely on their initial emotional reaction — whether something feels good or bad — as a guide to decision-making, without any further reflection (Slovic et al., 2007). Metaphors, as we have already indicated, are excellent tools for generating an immediate emotional response due to the vivid imagery and associations they evoke.
In one of our own experiments, participants read a brief paragraph about how the United States was addressing climate change by reducing carbon emissions (Flusberg, Matlock, & Thibodeau, 2017). For some, the paragraph described a metaphorical war against climate change, using emotionally charged, war-related language to frame the issue (“the entire country should be recruited to fight this deadly battle”). For others, these war metaphors were replaced with ones related to running a race (“The entire country needs to step up to the line and get in front of this challenging problem”). This metaphor still captures the idea of a competition with winners and losers, but it lacks the emotional intensity of war. The results showed that the war metaphors made people feel a greater sense of risk and urgency about the threat from climate change, leading them to express a greater willingness to engage in various conservation behaviors.
Metaphors can also be persuasive when paired with the right messenger. For example, people are more likely to be persuaded by someone they like and trust, regardless of their message (Sopory & Dillard, 2002).
In an interview for this project, photographer Aundre Larrow shared details on “The Last Expanse,” a wildlife conservation project funded by The North Face company. Larrow and a group of photographers went to Alaska to capture images of Alaska Natives and land that must be protected for wildlife. He and his colleagues were tasked with documenting the vastness of this land first hand and sharing what they saw as a way to produce narratives about Alaska Natives that build empathy and inspire others to protect their land. To achieve these goals, Aundre took polished photos of Alaska Natives showing their humanity, and used his iPhone and small Fujifilm camera to capture images of himself and his colleagues experiencing the area.
The latter photos were designed to express exploration and freedom as the viewer saw the land through the eyes of Aundre and his cohort. These images include wide landscape images, as well as images of him and his colleagues picking flowers. Metaphors of exploration were used to connect people who are far away to the land and inspire them to protect it. This was a strategic choice to engage people like him who are interested in travel, adventure and photography.
Five key takeaways
As you begin to use metaphors in your communications as tools for persuasion, here are five takeaways to keep in mind:
- Metaphors enhance the persuasive power of a message. According to one estimate, which pooled the results of many different studies, metaphorical framing results in a 6% bump in persuasion over comparable literal messages (Sopory & Dillard, 2002). Recent studies in experimental psychology and communications — many of which we have conducted ourselves — have found similar results, with effects ranging from about 2–12% depending on the topic and metaphor. This is a fairly modest effect size, but even small effects can have a big impact on a larger scale — the last U.S. presidential election was decided by fewer than 80,000 votes in a few key states in a country with a population over 320,000,000.
- Metaphors access the rational route to persuasion. Metaphors can motivate interest in a topic, getting people to put additional effort into thinking about the issue. Metaphors also make arguments more coherent, helping people rely on what they already know to organize their thoughts and draw conclusions — a process we describe extensively elsewhere in this series.
- Metaphors also access the emotional route to persuasion. Metaphors can enhance persuasion even when people are not motivated to think too deeply about a message. They do so by evoking immediate emotional reactions and by making the messenger seem more credible and dynamic.
- Several factors affect the effectiveness of a metaphor. When using metaphors in your messaging, there are many decisions to make: which metaphor should you use, where should it be placed in the message, and how many times should you use it? Research has shown that metaphors are generally more effective when they are placed toward the beginning of a message and when they are extended or used multiple times. We review these findings, among others, in much greater detail in one of the other essays in this series.
- Metaphors do not affect everyone in the same way. A given metaphor is unlikely to affect all audience members in the same way, and you should know the different factors that shape how people process and react to different types of messages. We devote an entire essay to how our values and beliefs impact how we process metaphor elsewhere in this series.
References
Citron, F. M., & Goldberg, A. E. (2014). Metaphorical sentences are more emotionally engaging than their literal counterparts. Journal of Cognitive Neuroscience, 26(11), 2585–2595
Elmore, K. C., & Luna-Lucero, M. (2017). Light bulbs or seeds? How metaphors for ideas influence judgments about genius. Social Psychological and Personality Science, 8(2), 200–208
Flusberg, S. J., Matlock, T., & Thibodeau, P. H. (2017). Metaphors for the war (or race) against climate change. Environmental Communication, 11(6), 769–783.
Slovic, P., Finucane, M. L., Peters, E., & MacGregor, D. G. (2007). The affect heuristic. European Journal of Operational Research, 177(3), 1333–1352
Sopory, P., & Dillard, J. P. (2002). The persuasive effects of metaphor: A meta‐analysis. Human Communication Research, 28(3), 382–419.
Thibodeau, P. H., & Flusberg, S. J. (2017). Metaphorical accounting: How framing the federal budget like a household’s affects voting intentions. Cognitive Science, 41, 1168–1182
