Anxiety doesn’t bring happiness, but it can bring success, especially when combined with intelligence.

Biographical information about Charles Darwin, for example, suggests he was plagued for much of his adult life with severe anxiety, but he was also substantially more intelligent than the average person.

As a result, although he appears to have felt miserable much of the time, his superior intellectual ability meant his anxiety was channelled into the highly-important work of worrying about the origin of species rather than some trifling matter, such as whether or not his socks matched his trousers. Someone with the same levels of anxiety as Darwin, but half his IQ, might well have ended up roaming the streets and eating from bins.

People who worry and are also blessed with high IQ tend to be visionaries, planners, creators and inventors. People who do not worry much at all, but are also highly intelligent, tend to be the successful implementers in front line, stressful situations. For example, fighter pilots typically have low levels of trait anxiety and are able to operate their planes on highly dangerous combat missions, the mere thought of which would give an anxiety-prone person sleepless nights.

Worry has been linked to physical health problems. In research at the University of Leiden in The Netherlands, teachers had their heart rate monitored 24 hours a day and kept a log of when they had episodes of worrying. Results show that when they were worrying, their heart rate increased by 2.55 beats a minute and variability went down by 5.76 milliseconds. Two hours after the episode, the heart rate was still 1.52 beats per minute higher.

The findings are important because heart rate is a measure of how hard the heart is working and a higher rate means it is having to work harder. Increased rates and reduced heart rate variability have both been linked to a higher risk of heart problems. Click here to see how heart rate variability is recorded at Spinewave.

While some worrying is necessary and protective, both too little and too much, it seems, can be hazardous. Excessive worrying is not only potentially unhealthy, it has absolutely no value and purpose. As the American novelist Alice Caldwell Rice, put it: “It ain’t no use putting up your umbrella ’til it rains.”

Adapted from Roger Dobson, Independent Online, 2011.