07:08
It evolved in humans along with intelligence to make them more adept at avoiding danger. A study of 42 people found the worst sufferers of a common anxiety disorder had a higher IQ than those whose symptoms were less severe. Scientists say their findings published in Frontiers in Evolutionary Neuroscience, suggest worrying has developed as a beneficial trait. Psychiatrist Professor Jeremy Coplan, of SUNY Downstate Medical Centre in New York, and colleagues found high intelligence and worry are linked with brain activity measured by the depletion of the nutrient choline in the white matter of the brain. He said: "While excessive worry is generally seen as a negative trait and high intelligence as a positive one, worry may cause our species to avoid dangerous situations, regardless of how remote a possibility they may be. "In essence, worry may make people 'take no chances,' and such people may have higher survival rates. Thus, like intelligence, worry may confer a benefit upon the species." The researchers made the discovery by monitoring activity in the brains of twenty six patients with generalized anxiety disorder (GAD) and eighteen healthy volunteers to assess the relationship between IQ, worry and the metabolism of choline. In the control group high IQ was associated with a lower degree of worry, but in those diagnosed with GAD it was linked with more. The correlation between IQ and worry was significant in both the GAD group and the healthy control group. But in the former it was positive and in the latter negative. Previous studies have indicated excessive worry tends to exist both in people with higher and lower intelligence, and less so in people of moderate intelligence. It has been suggested people with lower intelligence suffer more anxiety because they achieve less success in life. Worrying has also been shown to lessen the effect of depression by countering brain activity that heightens the condition.
