Those subjects who were the most startled by the unexpected or disturbing stimuli were also the ones who were most likely to favor such issues as increased defense spending, capital punishment, patriotism, and the Iraq War.
The people who were less startled by the stimuli, which included such things as a spider crawling across the face of a terrified person or loud, unexpected noises, tended to support foreign aid, liberal immigration policies, pacifism and gun control.
"We were probably as startled as the people who saw the picture of the spider to find that this works, and it is quite accurate," Alford says. "These are relatively straightforward tests, and the results are very crisp."
Alford says that this new study adds to past research which suggests that 30 to 40 percent of our notions and perceptions could have biological roots, adding, "The idea that there could be a biological component to our political ideology is fascinating."
The study is not the first to tie certain patterns of brain response to potential voting behavior. Marco Lacoboni, a professor of neurology at UCLA, conducted a study last year in which he used a functional MRI to peer into the brains of those presented with political imagery and see how their brain response matched up with their political leanings.
"This is a really clever study," Lacoboni says. "This research shows that all of our decisions are really rooted in biology. It's not just the rational thought of the brain that we use to reach decisions, but also our emotional ones."
He says part of the beauty of this most recent research is that it looks at a simple biological response -- the threshold of being upset by an external stimulus -- in relation to political philosophy.
Other brain researchers urge caution in interpreting the results of the relatively small study -- particularly at a time when many are scrutinizing what our brain may be doing behind our backs.
"I think we currently live in an environment of 'neuro-anything,'" says Joy Hirsch, professor of functional neuroradiology at Columbia University Medical Center in New York.
"Almost since functional imaging has sort of hit the press, you can't open an issue of the Science Times without finding an article about our brains in love, or neuro-economics, or our brains and politics," she says. "We have begun to think about complex behaviors in terms of the neurophysical machinery that drives them."
She adds that the study only shows a correlation -- which means it is impossible to tell yet whether being easily startled actually brings about what is known as protective decision-making, or if it works the other way around. It is a point with which Lacoboni agrees.
"It could also be the other way around," he says. "It is hard to tell it apart."
A Touchy Subject
The new research is the latest in a field of study that is seen by many as a potential minefield. Most people, after all, prefer to believe that their rational mind is in control of their decisions -- especially when it comes to casting their votes.
But other studies have suggested that whether we know it or not, certain areas of the brain may figure big in our political leanings. And to many, the idea that the tendency to be startled by a perceived threat could affect what Americans do in the voting booth on Nov. 4 is an unnerving one.
"We are in a very unique time when the population in general is experiencing the sensations of threat," Hirsch says. "This may be because of the economy, or it may be because of issues raised in the elections. We know that under conditions of threat the whole emotional system has a much greater influence toward biased decisions."
Alford further suggests that our genes could have a considerable impact on our daily decisions.
"If our genes have some connection to our political attitudes, then you have to have a lot of biology in between," he says.
But at what point does biology stop and reason begin? Alford says he is the first to admit that biology is not the whole story -- particularly when something as complex as politics is at play.
Alford offers the example of an individual who has genes that increase their susceptibility to breast cancer. This individual, he says, may only have a 10 to 20 percent greater chance of having the disease. In the same way, he says, the genetic or biological makeup of a person is only one contributor to their overall decision-making process.
"As soon as you start talking about biology, people immediately start thinking that biology must be deterministic," he says. "But the environmental component is much larger than the genetic component when it comes to the idea of susceptibility.
"We are not trying to talk about [biology] as being the root of all of public opinion, but we want to put it on the table."
Despite Anxiety, a Middle Ground?
So what might these findings contribute to the current political discourse? While those who edge away from defense-heavy politically protective policies may be inclined to label their opponents as easily frightened, Alford says his results should not be viewed as an excuse for further divisiveness.
"[The research] is less about our making decisions than it is about understanding how other people have come to opposite decisions," he says. "We may tend to think that they aren't paying attention to the right things, or to think that they aren't any good at working things out rationally, but maybe what someone sees is so obvious to them because they experience that immediate physiological response.
"If that's their starting point, it's not hard to see how they come to a decision that is different from someone who does not feel this."
Hirsch adds that the research may give Americans one more thing to think about as they arrive at their polling places for election day.
"People can evaluate their thinking to determine if they would make the same decisions if they were not feeling threatened, and think about its effect on their vote," she says. "They can decide to what extent they're responding to that and to what extent they're responding to a rational consideration of the issues."
And Alford hopes his work may help foster greater understanding between conservatives and liberals.
"Much of the current political discussion disparages people's intellectual ability," he says. "Maybe we can be a little less uncivil in our political discussions when we understand that not everyone has the same gut reaction or the same insulation from that reaction."