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Key points
- When you communicate an idea with a metaphor, you light up people’s sensory and motor neurons.
- You also activate emotions, prompt aha moments, and reward your audience with a sense of social interaction.
- When you’re trying to persuade, you might first seek a good story, but you may do better to seek a metaphor.
What’s the most persuasive way to convey a message? Many writers say, “Tell a story!” Nothing hooks like narrative. I’ve said so myself. But research shows stories have a rival for hooking power: metaphors. Metaphors can muscle into readers' minds just as much as stories can.
An example: Say a Category 4 hurricane is about to hit your town. How do you express the danger convincingly enough to get people to evacuate? Do you chronicle the big storm’s likely landfall? Or do you use figures of speech to tell people a “monster” storm is “poised to strike” and they will soon feel its “fury”?
We know the answer. David Hauser and Megan Fleming at Queen’s University (Canada) had people read a forecast of a storm using either literal or metaphorical descriptions. When they were metaphorical—using phrases like “poised to strike” and “fury”—people said they were much more likely to evacuate. They also said they expected more lives lost, more homes destroyed, and more days without power. [i]
Foster Simulation
George Orwell, in his classic Politics and the English Language, suggested that the persuasive power of writing depended on answering four questions: “1. What am I trying to say? 2. What words will express it? 3. What image or idiom [i.e., metaphor] will make it clearer? 4. Is this image fresh enough to have an effect?” [ii]
Based today on what we know from science, Orwell foresaw what psychologists have learned. There are at least four reasons metaphor has so much punch.
First, when you convey a concept with metaphor, which you normally construct with specifics, you fire up both the language circuits in the brain’s left hemisphere and sensory and motor circuits atop the brain. [iii] As an example, Simon Lacey and others at Emory University showed that texture metaphors—a “bubbly” personality versus a “lively” personality—activate sensory neurons. [iv] When people read specifics like that, they mentally reenact the experience in the part of the brain they would use in reality.
Similarly, Emilia Castaño and Gareth Carol at the University of Barcelona and the University of Birmingham (UK) had people read motion metaphors—for example, “stocks are tumbling.” People’s eyes rolled with the direction of motion the metaphor suggested. [v] In this case, the specifics spurred people’s reenactment of the motion by shifting their eyes downward.
Scientists call this reenactment “simulation.” What’s remarkable is that metaphors drive simulation not only in the brain’s neurons but also in the fibers of the muscles controlled by those neurons. The whole body gets in the act.
No surprise, then, that one recent study led by Yucheng Li at the University of Surrey (UK) found that a significant part of the impact of metaphors comes from specific language alone. [vi]
Elicit Emotion
Second, we know from research that metaphors and other figures of speech fire up the brain’s emotional circuits. Research in 2014 by Francesca Citron at the University of Lancaster (UK) and Adele Goldberg at Princeton shows that even the simplest metaphors—“She looked at him sweetly” versus “kindly”—aroused the amygdala.
Serena Mon at Princeton, along with Citron and others, later gauged emotional arousal and focused attention via a well-established surrogate, pupil dilation. Metaphors—“The matter was out of the editor’s hands”—consistently triggered more dilation than literal equivalents (i.e., "The matter was out of the editor’s control”). [vii]
Third, we know that many metaphors—"The speech he gave was poison”—require each of us, on the fly, to solve a mental riddle. How does poison relate to speech? The reader or listener solves that riddle to achieve comprehension. Research shows that people gain pleasure just from the small aha that comes from “getting” the riddle. [viii]
Fourth, when you construct a metaphor that’s new, you draw from the material in your unique mental library—your lifetime knowledge, experience, and imaginings. Readers infer from your metaphor what makes you tick—your goals, intentions, personality traits, and more. [ix] They do this by “mentalizing,” as scientists call it, which gives them a view of the real you behind the cerebral curtain. That, in turn, drives the neural reward that comes from their connecting with you socially. [x]
Cue a Narrative
Finally, metaphors often double as a story-like cue—when, for example, you say, “the situation was out of her hands.” That cue initiates firing in the brain across the swath of readers’ neurons activated by all stories. Your readers then become entrained neurologically. [xi] This so-called mental coupling, when your brain activity mirrors the reader's, gives stories power scientists are only beginning to grasp.
Taken together, the research on metaphor helps to explain why one meta-analysis in 2002 estimated that metaphorical language is about 6 percent more persuasive than literal language. [xii] Statistically, you’re often better off saying something with a metaphor than with literal words.
It also explains the findings of a 2021 study led by Vinodkumar Prabhakaran at Google Research. Prabhakaran and others used natural language processing to analyze 70,000 Facebook posts from 412 politicians. They found that even simple and conventional metaphorical language—“cure” crime, “tsunami” of immigrants—drove higher social media “participation,” “acceptance,” and “propagation.” [xiii]
The giants of writing like Orwell were right. When you next sit down to write, you should make it a priority to ask: How can I capture this idea in a metaphor? How can I elicit in my readers’ minds the vivid reenactment of the meaning of the metaphor—the sensations, “hot” and “cold” emotions, insightful aha moments, and the neural hook of narrative?
The use of metaphor comes with a warning, though. As Orwell said, don’t lean on tired, overused wordings, which are likely to numb the mind instead of activate it. [xiv] “Every such phrase,” he said, “anesthetizes a portion of one's brain.”
The right metaphor—recall Orwell’s “Big Brother” or “thought police”—lives long in the minds of your readers. It may cross the lips of not just people today, but of their children, and their children’s children.
References
[i] David Hauser and Megan Fleming, "Mother Nature’s Fury: Antagonist Metaphors for Natural Disasters Increase Forecasts of Their Severity and Encourage Evacuation," Science Communication 43, no. 5 (2021).
[ii] George Orwell, “Politics and the English Language,” 1946.
[iii] Scientists refer to this as “embodied cognition” or, more simply, “simulation.” For a book rich in experiments documenting this point by a cognitive scientist, see Benjamin Bergen, Louder Than Words (New York: Basic Books, 2012).
[iv] Simon Lacey, Randall Stilla, and Krish Sathian, "Metaphorically Feeling: Comprehending Textural Metaphors Activates Somatosensory Cortex," Brain and Language 120, no. 3 (2012).
[v] Emilia Castaño and Gareth Carrol, "Mental Simulation in the Processing of Literal and Metaphorical Motion Language: An Eye Movement Study," Metaphor and Symbol 35, no. 3 (2020).
[vi] Yucheng Li, Frank Guerin, and Chenghua Lin, "The Secret of Metaphor on Expressing Stronger Emotion," arXiv preprint arXiv:2301.13042 (2023). The impact of the muscle in this case came from the emotion evoked by the metaphors.
[vii] They attributed the dilation broadly to “richer meaning” and “engagement.” Serena K Mon et al., "Conventional Metaphors Elicit Greater Real-Time Engagement Than Literal Paraphrases or Concrete Sentences," Journal of Memory and Language 121 (2021).
[viii] John Kounios and Mark Beeman, "The Cognitive Neuroscience of Insight," Annual review of psychology 65 (2014). For more more on the relation of aha’s to the reward circuit, see Jasmin M Kizilirmak et al., "Learning of Novel Semantic Relationships Via Sudden Comprehension Is Associated with a Hippocampus-Independent Network," Consciousness and Cognition 69 (2019).
[ix] Andrea Bowes and Albert Katz, "Metaphor Creates Intimacy and Temporarily Enhances Theory of Mind," Memory & Cognition 43, no. 6 (2015).
[x] Prabaha Gangopadhyay et al., "Prefrontal–Amygdala Circuits in Social Decision-Making," Nature Neuroscience 24, no. 1 (2020).
[xi] For example, see Yangwen Xu et al., "Brain Network Reconfiguration for Narrative and Argumentative Thought," Communications Biology 4, no. 1 (2021).
[xii] Pradeep Sopory and James Price Dillard, "The Persuasive Effects of Metaphor: A Meta‐Analysis," Human Communication Research 28, no. 3 (2002).
[xiii] Vinodkumar Prabhakaran, Marek Rei, and Ekaterina Shutova, "How Metaphors Impact Political Discourse: A Large-Scale Topic-Agnostic Study Using Neural Metaphor Detection," Proceedings of the International AAAI Conference on Web and Social Media 15 (2021).
[xiv] Rutvik H Desai et al., "A Piece of the Action: Modulation of Sensory-Motor Regions by Action Idioms and Metaphors," NeuroImage 83 (2013).
