by James Geary
Metaphors, whether in poems or advertisements, only work with our active collusion. Metaphors are born plotters and we are their eager co-conspirators. They need us, as readers and consumers, to complete the link between deodorant and sexual prowess, fast food and immediate gratification, real toads and imaginary gardens. By stepping outside the constant commerce of imagery and affect, we can allow our actual needs and desires to surface.
Smoke may always get in our eyes, but where there is smoke there is not always fire.
Metaphor and the Brain
Bright Sneezes and Loud Sunlight
Which is brighter, a cough or a sneeze? Which is louder, sunlight or moonlight?
These queries may seem as strange as asking, “What kind of smoke are you?” or “How can a child think about a banana as a telephone?” But Lawrence E. Marks, a professor at the Yale School of Public Health, asked people these very questions and found that adults invariably equate brightness with loud, high-pitched sounds143. When queried about the relative brightness of coughs and sneezes, those surveyed immediately and overwhelmingly said a sneeze was brighter. When asked about the comparative loudness of sunlight versus moonlight, they just as immediately and overwhelmingly said sunlight was louder. Even children as young as four144 associated high-pitched sounds with brightness and low-pitched sounds with dimness.
Bright sneezes and loud sunlight are examples of synesthetic metaphors. Synesthesia is the ability to perceive a stimulus in one sense organ through a different sensory system as well. Some synesthetes perceive tastes when they see shapes; others hear sounds when they see numbers; some experience powerful feelings when they come into contact with specific textures, such as denim or sandpaper. Colored hearing is probably the most common form of synesthesia, with perhaps as many as 1 in every 2,000 people seeing distinct and vivid colors when they hear or even think about the sound of words, letters, or numbers.
Many of the metaphors we use every day are synesthetic, describing one sensory experience with vocabulary that belongs to another. Silence is sweet; facial expressions are sour. Sexually attractive people are hot; sexually unattractive people leave us cold. A salesman’s patter is smooth; a day at the office is rough. Sneezes are bright; coughs are dark. Along with pattern recognition, synesthesia may be one of the neurological building blocks of metaphor.
No one is quite sure how synesthesia works. Some researchers suggest that we are all born synesthetes, that synesthesia is the original way we experience the world. Newborn infants have an abundance of neural connections among the various sensory centers in the brain, connections that are gradually pruned back over time. According to this theory, synesthesia is the natural result of crosstalk among these massively interconnected neurons. Only after the age of about four months, when the cortex has sufficiently matured and the excess neural connections start to snap, does this innate synesthesia fade.
Synesthetic metaphors follow a remarkably consistent pattern145: words derived from more immediate senses like touch, taste, and smell describe the experience of less immediate senses like sight and hearing. Touch, taste, and smell are “experience-based sensations,” whereas sight and hearing are “object-based sensations.” An unpleasant taste, for example, is experienced much more viscerally than an unpleasant color. The former is felt as if it is inside the body; the latter is felt as if it emanates from an external object.
In a synesthetic metaphor, the source tends to come from the more immediate sense and the target tends to come from the less immediate sense far more often than the other way around.
Some researchers suggest that this movement from less to more immediate parallels the physiological development of the senses themselves146, thereby reflecting a basic mode of perception. Indeed, studies show that people find metaphors that follow this principle of directionality much easier to understand. Which may be why “sweet silence” (taste modifies sound) is common and “silent sweetness” (sound modifies taste) is not, and why “soft brightness” (touch modifies sight) makes sense and “bright softness” (sight modifies touch) does not.
Studies of nineteenth-century English, French, and Hungarian verse and twentieth-century poetry in Hebrew147 suggest that people from many different languages and cultures tune into the same sensory scale. The vast majority of metaphors studied in these texts point in the same direction—from more immediate to less immediate. In one experiment, graduate students at Tel Aviv University were asked to interpret forty synesthetic metaphors, which were derived from poems written in Hebrew and followed standard directionality, and those same synesthetic metaphors with the directionality reversed. Students found standard metaphors (“coarse whiteness” and “fragrant purple”) far easier to interpret than nonstandard ones (“white coarseness” and “purpled fragrance”).
The directionality of synesthetic metaphors follows the directionality of metaphor in general. Metaphorical thinking usually travels one way, appropriating concrete language—the words we use for everyday experiences and physical things and sensations—to describe abstractions like thoughts, feelings, emotions, and ideas. Juliet is the sun in ways that the sun is not and never will be Juliet. Stephin Merritt of The Magnetic Fields wrote a song about this—“Love Is Like a Bottle of Gin148,” which chronicles the many and varied ways love is similar to gin:
It makes you blind, it does you in
It makes you think you’re pretty tough
It makes you prone to crime and sin
It makes you say things off the cuff.
But the final verse acknowledges metaphor’s unidirectionality:
You just get out what they put in
And they never put in enough
Love is like a bottle of gin
But a bottle of gin is not like love.
Daniel Tammet is a synesthete as well as a savant. His memoir is titled Born on a Blue Day because his birthday—January 31, 1979—was a Wednesday and “Wednesdays are always blue149, like the number 9 and the sound of voices arguing.” Tammet has an especially rich type of synesthesia, in which he experiences individual numbers up to 10,000 as having specific colors, shapes, textures, movements, and even emotional tones. To Tammet, “Five is a clap of thunder150 or the sound of waves crashing against rocks. Thirty-seven is lumpy like porridge, while eighty-nine reminds me of falling snow.”
Neuroscientist Vilayanur Ramachandran, who has studied Tammet’s abilities, suggests that metaphor may have evolved from synesthesia151. The visual and auditory pathways in the brain are anatomically very close together. Over the course of evolutionary time, stray visual neurons could have branched out into neighboring auditory regions to transmit visual signals in response to sounds.
Thus, every time the neurons encoding letter sounds were activated in someone with colored hearing, there would be a corresponding activation of the neurons encoding color. “Can it be a coincidence152,” Ramachandran asks, “that the most common form of synesthesia involves graphemes [letters, numbers, punctuation marks, etc.] and colors and the brain areas corresponding to these are right next to each other?”
We all retain some synesthetic abilities, as the German-American psychologist Wolfgang Köhler showed in 1929 with his discovery of what has come to be known as the “bouba-kiki effect153.”
Köhler is best known for his demonstration of tool use among chimpanzees. But while working with chimps on Tenerife in the late 1920s, he also conducted an experiment in which he showed islanders two shapes—one round and amoeboid, the other sharp and spiky—and asked them to associate the made-up words “takete” and “baluba” with the shapes. Participants overwhelmingly associated “takete” with the sharp, spiky shape and “baluba” with the round, amoeboid shape.
Which one is bouba and which one is kiki? Image courtesy of Adam Somlai-Fischer, Prezi.com.
Around eighty years later, Ramachandran and cognitive psychologist Edward Hubbard repeated Köhler’s experiment, substituting the made-up words “kiki” for “takete” and “bo
uba” for “baluba.” They achieved the same result: around 98 percent of subjects identified the curved shape as “bouba” and the jagged one as “kiki.” They also found the same associations present regardless of language or culture. Other studies have shown that children as young as two and a half make the same choices. “This result suggests154,” Ramachandran concluded, “that the human brain is somehow able to extract abstract properties from the shapes and sounds—for example, the property of jaggedness embodied in both the pointy drawing and the harsh sound of kiki.”
The bright sneeze/loud sunlight exercise is essentially a variation on the bouba-kiki test. We extract the property of brightness from a sneeze because it is higher in pitch than a cough; we extract the property of loudness from sunlight because it provides more intense illumination than moonlight.
In fact, both sneezes and sunlight occupy the upper bands of their respective frequency ranges. Similarly, in the bouba-kiki test, the amoeboid shape and the “bouba” sound share aspects of roundness, while the sharp shape and the “kiki” sound share aspects of spikiness. When making associations like these, we instinctively find—or create—patterns. These patterns, in turn, connect the disparate sensory descriptions in synesthetic metaphors.
These primal perceptual associations may be hardwired into our brains, since even very young children associate visual and auditory stimuli155. In one study, infants listened to a pulsing tone until they became bored with it, as measured by a reduction in their heart rates. (Heart rates tend to decrease when we become habituated to a stimulus and tend to increase when we perceive a different, and therefore more interesting, stimulus.) Researchers then presented the infants with either a dotted line—the visual equivalent of a pulsing tone—or a continuous tone, and measured their heart rates again.
The infants’ heart rates picked up in response to the continuous tone, suggesting that they perceived the dotted line as similar to the pulsing tone and therefore less interesting than the continuous tone. Some metaphors may thus derive from synesthetic pattern recognition abilities that precede language acquisition.
If synesthesia is the result of cross-connectivity among the brain’s sensory regions, the same connectivity could explain why so many metaphors take the commonly shared world of physical sensation as their source and the private, abstract world of ideas, feelings, thoughts, and emotions as their target.
Take the mundane metaphors “She has a warm personality” and “He’s as cold as ice.” Warmth and cold are primal sensations, present even in the womb, that become associated over time with emotional states. The warmth of a mother’s embrace is linked in an infant’s mind with affection and security, the chill of its absence with rejection and fear. Warmth is such an essential sensation that non-human primate infants prefer heat to food. In one experiment, young macaque monkeys preferred a cloth surrogate mother (warmed by a 100-watt lightbulb)156 to an unheated wire surrogate mother, even when the wire surrogate was their only source of food.
Metaphor extends the vocabulary of these physical experiences to other circumstances that occasion the same kinds of feelings. Hence, we speak of friendly people as warm and unfriendly people as cold. There is evidence that these basic, universal physical experiences determine routine metaphorical associations.
In a classic study of how people form first impressions, social psychologist Solomon Asch gave two groups identical lists of character traits—except for one term. Half the participants received a list of adjectives including “intelligent,” “skillful,” “industrious,” “determined,” “practical,” “cautious,” and “warm”; the other half received the same list, except the word “cold” replaced the word “warm.” Each group then wrote a brief sketch of the person thus described. Those whose list included the word “warm” formed far more positive first impressions of the person than those whose list included the word “cold.”157
Asch observed that the words “warm” and “cold” dramatically affected people’s opinions, concluding that the associations emanating from these two little words are of special importance when assessing character. He also linked “warm” and “cold” to the formative role these sensations have in our early experience. “When we describe the workings of emotions, ideas, or trends of character158, we almost invariably employ terms that also denote properties and processes observable in the world of nature,” Asch wrote. “Every man deploys the language of naive physics when he is talking about psychological matters.”
In a cleverly updated version of Asch’s experiment, researchers casually asked participants to briefly hold a cup of hot coffee or a cup of iced coffee while en route to a room where they were meant to take a survey159. After arrival, they each read a description of a fictitious person and answered questions regarding their judgments of that person’s character. Both those who held the hot coffee and those who held the iced coffee read identical descriptions, but the hot coffee–holders described the person as more caring, generous, and friendlier (warmer) than the cold coffee–holders.
Another experiment showed that giving someone the cold shoulder can actually make that person perceive a reduction in temperature. In this study, participants recalled an experience of social exclusion and then estimated the temperature of the room in which they were sitting. A different group recalled an inclusive social experience and made the same estimate while sitting in the same room. Those who remembered an exclusion experience gave lower estimates of the room’s temperature—about 3 degrees Celsius lower—than those who recalled an inclusion experience.
In a related experiment, the same team engaged participants in a virtual game of “catch160.” Subjects threw a ball around online, supposedly with three other people. In fact, a computer program controlled the throws, ensuring that after two catches subjects in the exclusion group didn’t receive the ball for the rest of the game. Afterward, participants took an ostensibly unrelated marketing survey. Those who had been excluded from the game rated warm food and drink (hot coffee and hot soup rather than apples and crackers) as far more preferable than those in the control group, who had received the ball intermittently throughout the game.
Dispensers of icy stares, beware. You may actually make the target of your frosty glances feel colder.
This metaphorical effect is not limited to the laboratory, either. When Campbell’s Soup revamped its packaging, the firm added steam above the previously steamless photos of cream of potato, chicken noodle, and tomato soup because consumers said they felt more emotionally connected to the product if it looked warm.
Warmth—and the affective steam it produces—is such a hot attribute in advertising that Conquest, a London-based marketing consultancy, devised a way to measure it via metaphor. To gauge the effectiveness of marketing campaigns, Conquest asks consumer panels to use online avatars161 to express their attitudes toward particular brands. So instead of asking “What do you think of Brand X?” Conquest instructs: “Move your avatar to show how you feel about Brand X.” The closer the consumer moves the avatar, the “warmer” her feelings for the brand. And, according to Conquest, the affective warmth generated by an ad is predictive of its success in the marketplace.
Even something as apparently trivial as an object’s weight can have a synesthetic impact on the perceived heft of an issue.
Many common metaphors equate weight with importance162. We carefully weigh the pros and cons before making an important decision. When we’re flippant in the face of adversity, we fail to appreciate the gravity of the situation. Someone of little ability occupying a position of great responsibility is a lightweight. Serious issues requiring lots of reflection and soul-searching are, like, heavy, dude.
Dutch researchers handed college students clipboards in order to fill out questionnaires in which they were asked about the estimated value of foreign currencies and whether they wished to be consulted by the university committee in charge of distributing financial grants. Some clipboards weighed significantly more (2.29 lbs) than
others (1.45 lbs). Those with the heavier clipboards gave higher estimates of the foreign currency values and more often said that they should weigh in on the grant distribution. Participants with heavier clipboards judged the questions as weightier than participants with lighter clipboards, the researchers concluded, suggesting that physical weight prompts us to invest more cognitive effort when dealing with heavy things.
Similar studies have shown that people interviewing job applicants while holding a heavy rather than a light clipboard163 rated candidates as more important; people who handled rough jigsaw puzzle pieces described social interactions as more difficult than people who had handled smooth pieces; and people sitting on hard chairs were more rigid in price negotiations compared to people sitting in soft chairs. The metaphorical associations arising from these basic tactile sensations influenced participants’ perceptions of social situations, the researchers found.
As Ramachandran’s theory predicts, the associations observed in these kinds of studies typically involve brain regions that process both concrete and abstract information. The anterior insula, for example, is involved in the regulation of both body temperature (physical warmth) and interpersonal experience (psychological warmth). Ramachandran himself has identified the angular gyrus164 as an area that may be essential to certain forms of metaphorical thought.
Ramachandran and his team asked four patients, each of whom had impaired functioning in the left angular gyrus as a result of a stroke or a tumor, to explain the meaning of about two dozen proverbs and metaphors. The angular gyrus processes the senses of sight, hearing, and touch, among other functions. Presented with sayings like “The grass is always greener on the other side of the fence” and “An empty vessel makes more noise,” the patients interpreted the phrases literally.
When asked to explain the proverb “All that glitters is not gold,” for example, one participant said it was a warning “to be very careful when buying jewellery.” As a control, the researchers tested patients with damage to other brain regions; they interpreted the proverbs correctly. The four left angular gyrus patients also failed a version of the bouba-kiki test, while a group of people with intact left angular gyri passed it. Ramachandran posits that the right angular gyrus, which processes spatial information, could also be critical to metaphors like “He has a massive ego” or “She has a big heart.”
