Worrywarts, beware: all that fretting may be for naught. Anxiety has long been interpreted as a symptom of hyperawareness and sensitivity to danger, but a study published last December in Biological Psychology turns that logic on its head.

Tahl Frenkel, a graduate student in psychology at Tel Aviv University, asked 17 students who had anxious per­sonalities and 22 students who were more mellow to identify when they detected fear in a series of increasingly frightened faces. As expected, the anxious group spoke up before their calmer counterparts. The twist, however, came from the volunteers’ brain activity, recorded with electrodes on each student’s scalp. The brains of anxious subjects barely responded to the images until the frightened face had reached a certain obvious threshold, at which point their brains leapt into action as though caught off guard. Meanwhile nonanxious respondents showed increasing brain activity earlier in the exercise, which built up subtly with each increasingly fearful face. Although their behavioral response was slower, their brain activity suggests that the mellow subjects picked up on subtle differences in the images more quickly.

The result implies that worriers are less aware of potential danger—challeng­ing the common theory that anxious individuals are hypervigilant. Frenkel be­lieves that worrywarts’ low sensitivity to external warning signs causes them to be startled frequently by the seemingly sudden appearance of threats, which leaves them in a state of chronic stress. The brain activity in nonanxious subjects, Frenkel explains, may be evidence of an “early subconscious warning mechanism,” which keeps them cool, calm and collected. [For more on how to ease chronic worrying, see “Why We Worry,” by Victoria Stern; Scientific American Mind, November/December 2009.]

This article was published in print as "The Fallacy of Fretting."