In his speech at the memorial service for the victims of the Tucson shooting, President Obama urged Americans to “make sure that we’re talking with each other in a way that heals, not in a way that wounds.” Everyone has experienced the power of words to ease or inflict emotional pain. What is less commonly experienced, consciously, at least, is the powerful way that metaphors in general—and metaphors in political rhetoric and imagery, in particular—influence our attitudes, beliefs, and actions.

It is impossible to attribute a specific act of violence to a general program of political sloganeering, just as it is impossible to attribute a specific extreme weather event to climate change. So ‘Did Sarah Palin’s placement of cross hairs on an electoral map that included Representative Gabrielle Giffords’ district inspire last weekend’s attack?’ is the wrong question to ask. Instead, we should ask, ‘How do metaphors frame issues in ways that either promote engagement and encourage estrangement?’ The political climate, like the physical climate, is something we all create and influence. If it gets too hot, we all suffer.

In contrast to Obama’s conciliatory tone, Sarah Palin came out with all guns blazing in her video message denouncing those who blamed martial political imagery for the violence. In doing so, she used another martial metaphor, accusing the media of using a “blood libel.” The term “blood libel” refers to a piece of anti-Semitic propaganda originating in the Middle Ages in which Jews were falsely accused of using the blood of murdered children to make matzo, or unleavened bread.

Metaphorical phrases like these do not only cause offense; they trigger powerful associations that shape opinions and actions.

Psychologist Thomas Gilovich demonstrated the power of these metaphors in a landmark study in which he asked a group of Stanford undergraduates to imagine that they were high-ranking officials in the U.S. State Department. He informed them that a small democratic country of no vital interest to U.S. national security had been attacked by a moderately powerful communist or fascist country and had asked the U.S. for help. What should the U.S. do—nothing, appeal to the United Nations, or intervene?

Gilovich then gave each student one of three different descriptions of this hypothetical foreign policy crisis, each of which contained a few minor associations and a few familiar names designed to trigger different historical analogies. One scenario featured allusions to World War II, another featured allusions to Vietnam, and the third was historically neutral. In the World War II scenario, minorities were described as fleeing in boxcars on freight trains, for example. In the Vietnam scenario, minorities were described as fleeing in small boats up the coast.

These historical cues were, of course, entirely irrelevant to the decision participants had to make. Nonetheless, subjects given the World War II scenario made more interventionist recommendations than the other two. The Vietnam and control groups both tended to recommend a hands-off approach. Gilovich quizzed students afterward, and none was aware of the historical allusions embedded in the descriptions—and all denied that these associations could have influenced their decisions.

Because metaphors frame the way we look at issues, and they do it without our conscious awareness, they also constrict the range of possible responses we can have to those issues. Metaphors trigger largely associations in our minds, and we naturally start to view things within the confines of those associations—even if those associations are irrelevant, or even counterproductive, to the issue at hand. The more the metaphors are repeated, the more propitious or pernicious they become.

In his speech in Tucson, Obama emphasized the metaphor of family. “For those who were harmed, those who were killed,” he said, “they are part of our family, an American family 300 million strong.” He even personalized the metaphor by naming individual victims and directly equating them with our own loved ones: “Phyllis—she’s our mom or our grandma; Gabe our brother or son.” Obama metaphorically highlighted the fact that, as Americans, we share one blood; Palin metaphorically accused some Americans of spilling the blood of other Americans.

Which metaphor encourages us to “constantly widen the circle of our concern so that we bequeath the American Dream to future generations,” as Obama also said in his speech?

Political crises are not resolved simply by choosing alternate metaphors, of course. But metaphors matter—a lot. Last March, in the midst of the healthcare reform debate, Sarah Palin posted a message on her Facebook page, ostensibly about the college basketball teams competing in March Madness, that re-enforced her martial metaphors: “The crossfire is intense, so penetrate through enemy territory by bombing through the press, and use your strong weapons—your Big Guns—to drive to the hole. Shoot with accuracy; aim high and remember it takes blood, sweat and tears to win.”

This text is strangely similar to George Carlin’s famous routine comparing gridiron clashes with baseball games. “In football,” Carlin noted, “the object is for the quarterback, otherwise known as the field general, to be on target with his aerial assault, riddling the defense by hitting his receivers with deadly accuracy, in spite of the blitz, even if he has to use the shotgun. With short bullet passes and long bombs, he marches his troops into enemy territory, balancing this aerial assault with a sustained ground attack which punches holes in the forward wall of the enemy’s defensive line. In baseball, the object is to go ‘home’ and to be ‘safe’.”

Metaphorical choices don’t just reflect opinions and actions; they help shape them. So it is imperative to carefully and consciously choose the metaphors we use and to be vigilant about those used by others. In confronting intractable political issues, it makes all the difference in the world whether the next step is sudden death or extra innings.

Blatant self-promotional message:

Want to know more about metaphor? Check out I Is an Other: The Secret Life of Metaphor and How It Shapes the Way We See the World, out on February 8.