BBC Horizon’s – The Truth About Personality

Yet another great BBC Horizon¬†production presented by Michael Moseley. This time Dr Moseley is on a quest to find out more about personality. In part fueled by a desire to cure 20 years of chronic insomnia and to find out whether he can change his self-confessed pessimistic outlook on life. As a qualified doctor and BBC presenter I guess his pessimism hasn’t served him too badly so far!

In the 70s, Oxford Ohio was the seat of an interesting social experiment. People over 50 years old were questioned and followed over several years to learn more about aging. Professor Becca Levy (Yale University) analysed the data and found that it was in fact attitude that determined longevity. People with positive beliefs about aging live an average of 7.5 years longer than those with negative beliefs. They put it into context by noting that curing cancer would only add 3-4 years life expectancy.

One of the most important personality traits is whether we’re optimistic or pessimistic. Being pessimistic, anxious and neurotic affects our reaction to the world but how can we objectively measure this? Well, it’s been found that these traits lead to an increased activity of the right frontal cortex compared to the left. To measure this, Dr Moseley visited Professor Elaine Fox (University of Essex). It turned out he had 3 times more activity on the right than the left. His pessimism was confirmed! In addition, Prof Fox had him take a test to check his reaction time to dots on a screen. The dots were either preceded by an angry face or a happy face. His reaction time was a lot shorter when the dots were preceded by an angry face. Possibly because he had a habit of focusing more on the negative than the positive.

At MIT Professor Rosalind Picard asked him to wear a wristband whilst they had a chat. The wristband measured his skin temperature and electrical conductivity which are both affected by the autonomic nervous system and so gave a good indication of his emotional state. Dr Moseley’s baseline levels were high, suggesting heightened arousal, even though he felt relaxed. That’s because intriguingly, the body tells us about a change in state before the mind realises.

So now he had evidence indicating he was pessimistic and possibly a little anxious. What could he do about it? Professor Fox suggested using Cognitive Bias Modification (CBM). He simply had to look at screen shots of mainly unhappy faces and spot the one happy face…repeatedly. In theory this decreases the unconscious negative bias by breaking the habit of looking for the negative. Evidence has shown that it helps combat anxiety but not depression. Dr Moseley confided in being self- absorbed, worrying about the past, stressing about the future and as a result being unable to savour the present. So he decided to use CBM 3x/week for about 7 weeks.

His next encounter was with Andy Puddicombe, a former Buddhist monk, who now teaches mindfulness meditation. He said that 10-20 mins of meditation a day would be enough to make a psychological and physiological difference. MRI studies of meditators have shown they have increased grey matter in areas that regulate emotion and increased activity in the left prefrontal cortex which is a centre for positive emotions. The meditation he was taught consisted of focusing on breathing. With training, the mind wanders less down negative habitual routes. So in addition to his CBM training, Dr Moseley decided to do 7 weeks of daily mindfulness meditation.

How does our personality come about? Is it nature or nurture? Professor Tim Spector (King’s College London) has studied identical twins for over 20 years. He believes that 40-50% of personality is based on genetics. His study of discordant twins has revealed that genes can change through life! This is the fascinating field of epigenetics. Genes can be switched on or off by stressful life events. If they can change in one direction they can change in the other, which means we can regain control of our genes!

Professor Michael Meaney’s (McGill University) studies on mice have demonstrated that the effect of good maternal care (more contact, licking) protects rats from anxiety by modifying genes and these changes are transmitted through generations. The hippocampus controls stress, emotion and memory. Better mothering increases glucocorticoid¬†receptors in this part of the brain.

After 7 weeks of CBM and mindfulness meditation Dr Moseley confessed he was sleeping better than he had in the last 10 years! He repeated the tests and measurements with professor Fox and found that he now had less than 2 times more activity in the right frontal cortex than the left. The activity in the right frontal cortex was half of what it previously was. His reaction time was now better when preceded by a happy face than an angry face, which suggested he may be noticing more of the positive in his daily life.


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