A lot of concepts that are central to the human experience are abstract, things we can’t directly see or touch. For example, relationships, ideas, and time are concepts that we think and talk about a lot. We commonly use concrete language to talk and think about these things — we use metaphors.
A recent review paper I worked on with Paul Thibodeau and Lera Boroditsky focuses on the role that metaphors in language play in shaping our thoughts. We summarize numerous studies that show the power of metaphor to guide the way we think, and discuss cases in which metaphors are most influential. Here are some of my favorite takeaway points from the paper.
A lot of studies that show that metaphors shape the way we think
Climate change, illnesses, the stock market, crime… These are all important issues, and are among the many domains that have been investigated in “metaphor framing studies.” In these studies, researchers present information about the topic to their participants. The information usually includes one metaphor that the researchers intend to test. Other participants get identical information about that same issue, but their information includes a different metaphor. The researchers ask everyone the same opinion questions after, and measure differences in belief that can be attributed to the metaphor people read.
This method has been used to reveal that referring to a war against global warming encourages people to feel urgency for reducing emissions than a race against global warming (more on this study here).
Similar results have also revealed that ideas seem more exceptional when they’re referred to as light bulbs than as seeds. And that conflict hurts people’s idea of their relationship more when the relationship is described as a perfect union than as a journey. These studies and many others show that when we encounter a metaphor in natural language, we often reason about that metaphorical idea in ways that are consistent with the literal idea used to describe it.
Metaphors are most influential when people have just the right amount of prior knowledge
In order for the phrase Crime is a beast to shape the way you think about crime, you have to know something about crime already, and you have to know something about beasts. We review studies that show that when people don’t know enough or care enough about one of the topics, metaphors don’t persuade them. For example, students who liked sports were more in favor of a senior thesis requirement when it was framed with sports metaphors than when it wasn’t, but students who didn’t like sports were not affected at all by the sports metaphors.
At the same, metaphors are most persuasive when people don’t have too much knowledge or strong prior beliefs about the topic being described. For example, people who have deep-seated beliefs about crime are not as swayed by crime metaphors as those who don’t. In other work, when an experiment was designed to make people feel unconfident in their economic knowledge (by giving them a hard quiz), they were more likely to reason about an economic situation (a company’s bankruptcy) in metaphor-consistent ways than people who got an easy quiz, which inflated their confidence.
Metaphors are most effective, then, when people have not too much, or not too little knowledge on a topic — their knowledge level has to be just right.
Metaphors shape memory and attention
It’s useful for us to know that metaphor shapes thought, and when metaphor shapes thought, but it’s also important to work to understand how it does so. In many metaphor framing studies, participants receive a passage with a metaphor, and tend to reason in metaphor-consistent ways, but what’s going on in the space between those events? What is the mechanism through which metaphors exert their effects?
It seems that one way metaphors shape thought is by guiding what we pay attention to in a communication, and therefore what we remember about it. For example, an eye-tracking study revealed that people move their eyes in a path-like motion while they process metaphorical sentences, like “The road goes through the desert” (remember, roads don’t “go” anywhere – they stay still!) compared to literal sentences, like “the road is in the desert.” Eye movements are often used as an indicator of what people are paying most attention to, suggesting that metaphors can shape how people pay attention to incoming information.
In addition to reviewing what cognitive science has revealed about the relationship between metaphor and thought, our paper also reviews what we don’t yet know. To me, one of the most important areas for future work is to understand how insights from these theoretically informative and tightly controlled lab studies can be applied to addressing real-world issues. We’re starting with a solid foundation that shows us that metaphor does shape thought, but we still have much to do to figure out how to apply that knowledge.