Isaac Newton was a classic neurotic. He was a brooder and a worrier, prone to dwelling on the scientific problems before him as well as his childhood sins. But Newton also had creative breakthroughs--thoughts on physics so profound that they are still part of a standard science education.
People who score high on neuroticism in personality tests tend to have negative thoughts and feelings of all types, struggle to cope with dangerous jobs, and are more likely to experience psychiatric disorders within their lifetime. The most popular explanation for why people are neurotic comes from British psychologist Jeffrey Gray, who proposed in the 1970s that such individuals have a heightened sensitivity to threat. He reached this conclusion after observing how antianxiety drugs reduced the sensitivity of rodents to cues of punishment and also helped to relax and liven up psychiatric patients.
"Gray had a useful and logical theory, but the problem is that it doesn't account for the full spectrum of neuroticism--it's pretty difficult to explain neuroticism in terms of magnified threat perception because high scorers often feel unhappy in situations where there is no threat at all," says paper lead author Adam Perkins, a personality researcher at King's College London. "The second problem is, there's literature showing neuroticism scores are positively correlated with creativity; and so why should having a magnified view of threat objects make you good at coming up with new ideas?"
The psychiatric relevance of this theory was highlighted by psychiatrist and coauthor Danilo Arnone, who argued that this novel cognitive model might help to explain the ruminative thinking pattern seen in depression and is complementary to the already defined role of the subgenual prefrontal cortex in the aetiology of mood dysregulation.
The overthinking hypothesis also explains the positives of neuroticism. The creativity of Isaac Newton and other neurotics may simply be the result of their tendency to dwell on problems far longer than average people. "I keep the subject constantly before me, and wait till the first dawnings open slowly, by little and little, into a full and clear light," Newton once said of his problem-solving method.
Source material from CELL