In honor of Halloween, Scientific American tell us why and how we're afraid.

What's scarier, a deadly snake slithering across your path during a hike or watching a 1,000-point drop in the stock market? Although both may instill fear, researchers disagree over the nature and cause of this very powerful emotion.

"When you see the stock market fall 1,000 points, that's the same as seeing a snake," says Joseph LeDoux, professor of neuroscience and psychology the Center for the Neuroscience of Fear and Anxiety based at New York University. "Fear is the response to the immediate stimuli. The empty feeling in your gut, the racing of your heart, palms sweating, the nervousness—that's your brain responding in a preprogrammed way to a very specific threat."

Does this mean that watching Elisabeth introduce Sarah Palin is like watching the stock market plunge a thousand points?

There's a great interview with neurologist Robert Burton on Scientific American. He talks about his research into why we are so convinced we’re right even when we’re wrong.

The ramifications of this kind of work impact politics, economics, medicine, and any number of other fields. If we know why we make wrong choices, then we can learn how to begin making informed ones about who we want as leaders, how to spend our money, and how to care for our health. Burton says:

I suspect that retreat into absolute ideologies is accentuated during periods of confusion, lack of governmental direction, economic chaos and information overload. At bottom, we are pattern recognizers who seek escape from ambiguity and indecision. If a major brain function is to maintain mental homeostasis, it is understandable how stances of certainty can counteract anxiety and apprehension. Even though I know better, I find myself somewhat reassured (albeit temporarily) by absolute comments such as, "the stock market always recovers," even when I realize that this may be only wishful thinking.

This reminds me of the study, reported by the Washington Post, that found that Republicans have a stronger startle response than Democrats. They are more likely to act without really thinking. It seems that, more often than, the intellect is something to be ridiculed. David Brooks, a Conservative himself, writes in today's NYT: "[O]ver the past few decades, the Republican Party has driven away people who live in cities, in highly educated regions and on the coasts . . .What had been a disdain for liberal intellectuals slipped into a disdain for the educated class as a whole."

This kind of reaction affects more than just Republicans, however. Burton says that he has "known many first-rate, highly concerned and seemingly well motivated physicians who, nevertheless, operate based upon gut feelings and personal beliefs even in the face of contrary scientific evidence. Burton goes on to say, "In short, please run, do not walk, to the nearest exit when you hear so-called leaders being certain of any particular policy. Only in the absence of certainty can we have open-mindedness, mental flexibility and willingness to contemplate alternative ideas."

Hallelujah.