Is this a case of scientists discovering something the rest of us already know? Well, yes and no. Most people probably realize that if they are fighting traffic on the way home, and worried about work, they are more likely to fly off the handle at the motorist who cuts in front of them. Stress increases anxiety and fear, or at least that's what our everyday experiences suggest.
And not all stress is bad. If there's no stress at all, little is being done. There is some stress in excelling at anything, so attempting to eliminate stress in some cases is counterproductive.
But too much stress can be crippling, leading to the kind of mental disorders that are of great concern to the people at the National Institute of Mental Health. So measuring precisely how stress affects such things as anxiety is good science, even if most of us think we already know the answer.
And we should expect some significant response to even relatively mild stress, especially when it's dark. That's OK, according to John Krystal, editor of Biological Psychiatry, who commented on the report.
"Just remember that it's normal to jump when someone shouts 'boo,'" he said.
Especially when it's dark and it's Halloween.
Lee Dye is a former science writer for the Los Angeles Times. He now lives in Juneau, Alaska.