I recently read about a study that indicates that the feeling of fear allows humans to see larger, less defined shapes better, while hindering our ability to see finer details. This is probably due to the fact that the evolutionary benefit of seeing a blurry beast running in our direction is more important than the benefit of recognizing whether the beast is a wolf or a bear.
What does this mean for our current world reality? Maybe this shows why stock market busts are often more reckless and more rapid than stock market booms - once enough fear is created, the details become less important. The big picture of potential financial catastrophe is sharpened while the positive details of particular companies are temporarily forsaken. Ignoring the details for too long is costly. Fear might save us in the short-term, but details are vital for long-term prosperity.