How the Brain Does Metaphor

Metaphor isn’t just a literary device; it’s hard-wired into our brain

Metaphor is a powerful tool; it allows us describe things in new, enriching ways by comparing two things that aren’t necessarily very similar on the surface. This enhances understanding. For example, saying “Ella is walking a tightrope with her grades this semester” is much more rich and descriptive than saying “Ella’s having trouble keeping her GPA high.” The metaphor paints a vivid image in our heads of Ella. We envision her walking along a tightrope suspended in midair, attempting to keep her grades up. One wrong move, and she is sent plummeting down to the hard, unforgiving ground. Ella’s situation becomes more cinematic, dramatic, and risky. We have a fuller, more multi-dimensional understanding of the severity of Ella’s predicament because of metaphor.

Metaphor’s Emotional Punch

Using metaphor not only makes things easier to understand, but also makes them more impactful and emotionally salient. Poetry, creative writing, film, paintings: all are rife with metaphor. Why? Because figurative language is so much more moving than literal speech. In my previous post The Mega Power of Metaphor, I referenced a scientific study which found that people’s brains have a stronger emotional response to sentences when metaphors are used. Metaphors are powerful tools.

Metaphor in Everyday Life

As we all know, metaphor and other types of figurative language aren’t just reserved for poetry and art; we also use them in daily speech. When somebody we love gets injured emotionally or physically, we say we “feel their pain” (even though we cannot literally feel their pain.) When someone does something that deeply offends us, we say they “leave a bad taste in our mouth” (even though we cannot taste depravity). Would you believe me if I said these common phrases have a neural basis?

According to professor and renowned behavioral biologist Robert Sapolsky, they do indeed. I took Sapolskly’s Human Behavioral Biology class at Stanford, and he repeatedly talked about what he called the “metaphorical brain.” Sapolsky argues that our brain is pre-wired to produce and understand metaphor. In fact, specific brain regions can be linked to commonly used metaphors. Below are some examples to illustrate what exactly that means.

Brain Regions that Make Metaphor

Insular Cortex

Take the insular cortex, for instance. This part of the brain is responsible for feelings of visceral disgust. When you eat or smell something gross, the insular cortex activates. Interestingly, it also responds when you witness or imagine moral depravity. People’s insular cortex will activate when somebody does something they deem to be morally disgusting–like tripping an old lady, for instance. Interesting right? As human brains evolved to become more complex and developed higher thought processes, the part of the brain responsible for gustatory disgust began dealing with moral disgust as well. That’s why we say immoral people “leave a bad taste in our mouth”. According to our brain, there is no difference between moral disgust and olfactory/gustatory disgust.

This could explain why people are more likely to wash their hands after talking about past moral transgressions (Zhong and Liljenquist, 2006). They are metaphorically cleansing themselves of wrongdoings, eliminating the feelings of visceral disgust produced by insular cortex. It could be why the phrase “washing away your sins” exists.

Anterior cingulate

The anterior cingulate is another brain region involved in symbolic thinking. This brain region is implicated in pain perception and empathy. It activates both when you are feeling pain (for example, when you stub your toe) AND when someone you love feels pain (for example, when your sister stubs her toe). In some sense, your brain cannot tell the difference between your pain and someone else’s pain. So, the phrase “I feel your pain” is actually quite true on a neurological level.

Animal studies also support the idea that you really can (neurologically) feel someone’s pain. An experiment conducted at Oregon Health and Science University exposed one group of mice to pain-inducing stimuli while a second group of “bystander” mice looked on without directly being harmed. The study found that both the pain-experiencing mice and the bystander mice became more sensitive to pain afterwards (a common response to physical pain). In other words, the bystander mice “felt” the pain of the other mice and reacted as though they themselves had been harmed. Mice that couldn’t see the first group of mice being harmed did not experience heightened pain sensitivity.

More Examples of the Metaphorical Brain

So, evidence suggests that the brain is a natural metaphor machine. Brain regions like the insular cortex and anterior cingulate conflate the metaphorical with the literal–confusing physical disgust with moral disgust or our pain with someone else’s pain.

Below are some additional interesting studies that demonstrate how the brain blurs the lines between the literal and the metaphorical.

  1. The Warm Person: In this study conducted by Lawrence Williams of the University of Colorado and John Bargh of Yale, subjects were briefly asked to hold either a hot or cold drink. Then, they read a description of an individual and rated their personality. Interestingly, if they had held the warm drink, subjects rated individuals’ personalities as warmer — more friendly, kind, and inviting. If they were given the cold drink, they tended to rate people’s personalities as cooler — more distant, standoffish, and unfriendly. The brain was using the metaphorical meanings of warm and cold to provide information about personality!
  2. The Serious Situation: In another one of Bargh’s studies, subjects were given either heavy or light clipboards containing resumes of job applicants. Those who were given the heavy clipboard tended to judge the candidates to be more serious than did those given the light clipboard. This may explain why we often use phrases like “the gravity of the situation” or “weighty matter” when describing a serious predicament.
  3. The Rigid Employee: Here’s another experiment by Bargh and colleagues that metaphorically relates tactile sensation to social interactions. In this study, subjects touched either a soft blanket or hard wooden block. Then, they were told a story about a workplace interaction between manager and employee and asked to rate the employee’s personality. Subjects who handled the wooden block rated the employee as more rigid, stable, and strict. Again, the brain seems to be taking the metaphorical literally.

These findings suggest that metaphors aren’t just artistic tools for use in poetry and art . Instead, they permeate our daily lives, influencing how we view the world. On a neurological level, there isn’t much difference between the figurative and the literal, the morally disgusting and the viscerally disgusting. Metaphors are ingrained in the very organization of our brain — we cannot escape them. That is why they are so powerful.

So next time you write a poem, draft a speech, or create marketing copy, be sure to throw in a metaphor or two.

MAIN SOURCE: SAPOLSKY, ROBERT. “HUMAN BEHAVIORAL BIOLOGY.” STANFORD COURSE. HEWLETT 200, STANFORD, CA. SPRING 2018. LECTURE.

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Documenting insights about humanity, culture, and design. // Self-experimenter, UX Designer @ Google.

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