Thomas Eric Duncan, the first person to die of Ebola in the United States, came to this country by air. He did not cross the U.S.-Mexico border. And yet, for some conservative politicians, the arrival of Ebola here has piqued concerns about the security of the southern border.
"If people are coming through normal channels [with Ebola]," Senate candidate Scott Brown said recently in a radio interview, "can you imagine what they can do through our porous borders?" Other politicians are like-minded, calling for the outright closure of the border.
The scenario that Ebola enters the U.S. through Mexico is not outright impossible. It's just unlikely considering the facts. There have been no reported cases of Ebola in Mexico or Central America. Conceivably, it could be possible for someone infected with Ebola to enter the United States in a car from Mexico. But for that to happen right now, the Ebola carrier would have had to spend some time in West Africa before heading to Mexico. Then, the person would have to travel to the U.S. before the disease's symptoms kick in, which can take two to 21 days after exposure.
So why are conservatives so concerned about the southern border in the wake of Ebola? Psychology has an answer: Ebola is making conservatives more conservative.
Let's step back.
It's likely that humanity has evolved to have people with liberal and conservative minds in any given society. According to mounting psychological research, liberals tend to be open to new experiences, while conservatives seek to protect what they already have. Often these mind-sets result in political clashes. But the tension between liberal brains and conservative brains makes sense for survival. There are times when it's important to discover new things, and there are times when it's important to avoid dangers. The tension between those two strategies is what has fueled human political conflict for millennia as groups argue over how a society should be run. But it has also kept us alive.
Through this evolutionary lens, conservatism is a strategy to protect a society from harm from both outsiders and diseases. Ebola hits this exact conservative nerve—it's a deadly disease from a foreign country. Ebola is activating all the evolutionary alarms of the conservative mind.
John Hibbing, a leading researcher in political physiology, explains it like this: "What we've found is pretty clear and consistent—that conservatives tend to have more reaction to negative things. We like to see not just if they report in a survey-type format whether they are bothered by that, but actually physiologically if there has been a change."
In his experiments, Hibbing often attaches electrodes to liberal and conservative participants' skin and then shows them disturbing images, such as a man eating a handful of worms. In these tests, conservatives sweat more (i.e., have a stronger gut reaction) in response to the disgusting stimulus. And when Hibbing hooks participants up to eye-tracking machines, he finds conservatives monitor more closely the things that make them squirm. So they are more readily provoked and more vigilant. These differences between liberals and conservatives are likely deep seated in the brain: scientists have found that conservatives tend to have larger amygdala, a region of the brain involved in fear processing, than liberals do.
And when people become fearful, they're more likely put distance between their group and others. "Since out-group members are more likely to carry pathogens to which members of the in-group have not yet developed immunity, avoidance of out-groups can be adaptive when the threat of the disease is salient," UCLA researchers wrote in a 2006 paper.
In that paper, the researchers found that when participants were primed to think about disease, they "increased their preference for the American over the foreigner and increased their attraction to the American." They became less receptive to outsiders, just like certain politicians seem to be doing right now in the wake of Ebola.
"It doesn't mean that conservatives are deeply flawed," Hibbing said. "From an evolutionary point of view, responding to negative things in the environment makes a lot of sense. You need to be aware of them."