One trait is linked to a worse score in intelligence tests.
People with unstable emotions tend to get lower scores on IQ tests, studies find.
This may, though, be down to nervousness while taking the test.
In fact, people who are neurotic may have higher IQs than the standard test reveals.
Neuroticism, one of the five major personality traits, encompasses unstable emotions, anxiety, self-consciousness and irritability.
People who are higher in neuroticism may also sleep poorly, the study’s authors explain:
“High scorers tend to be sensitive, emotional, worrying, moody, frequently depressed, often sleep badly and may suffer from various psychosomatic disorders.
Low scorers tend to be secure, hardy and generally relaxed even under stressful conditions.”
The conclusions come from two studies, the first of which was conducted on 646 Dutch twins.
The results showed that people higher in neuroticism got lower scores on an IQ test.
The link is down to genetics, the researchers concluded.
However, a second study gave IQ tests to 213 people and split them into two groups depending on how anxious they were.
The results of this study showed that the more nervous people were, the lower their IQ scores.
By statistically removing the effects of anxiety, though, the researchers were able to show that highly neurotic people are just as intelligent.
The authors conclude:
“Neurotics become more anxious under testing conditions, and this anxiety affects their performance on the IQ tests.
It is therefore proposed that Neuroticism is not related to intelligence per se, but to intelligence test performance, which has been proposed in the past (Eysenck, 1971).
This suggestion implies that IQ tests may underestimate the true intelligence of Neurotic individuals.”
The studies were published in the journal Personality and Individual Differences (Bartels et al., 2012; Moutafi et al., 2006).
