Researchers are slowly uncovering how personality can affect our health. (Photo: Shutterstock)
Researchers are slowly uncovering how personality can affect our health. (Photo: Shutterstock)

Research points to personality's effect on our health

Angry and hostile people are more prone to cardiovascular disease than others, while anxious and depressive types have a high risk of developing dementia. Studying the connection between personality and illnesses is a hot topic among scientists.


Cynical and distrustful people are more prone to dementia than others, suggests a Finnish-Swedish population previously described on ScienceNordic.

Read about the study here: Cynical people are more likely to develop dementia

The study follows a number of research findings that’ve previously established connections between personality traits and poor health.

“The Finnish article fits an extensive and comprehensive research tradition that’s grown during the 1980s and 1990s, as psychology researchers are starting to agree more on what personality is,” says professor of psychology Erik Mortensen of the Department of Public Health at the University of Copenhagen.

Personality is the set of lasting psychological traits that characterise a person. It’s this particular set of traits that makes people recognisable after ten years have passed -- even without looking at them.

Studies of twins and adoption have shown that individual differences in personality are to a certain extent determined by genetic factors but are also shaped by the environment the child grows up in.

“Personality is developed during our upbringing but we are born with genetic variations that give us the potential to develop in a certain direction,” says Erik Mortensen, professor of psychology at the University of Copenhagen.

“The most important dimensions of personality have been agreed upon so more and more knowledge about the significance of personality to life and health is being accumulated,” he says.

Anger and hostility is harmful to health

According to Mortensen, the developments in psychological research have led to an increased interest in the question of whether certain personality traits make people predisposed to developing various illnesses.

In 2012 Mortensen co-authored a comprehensive study on the connection between hostile personality traits and age-related loss of intelligence.

Earlier, in 1983, an American study showed that hostility can increase the risk of developing cardiovascular diseases and more studies have since confirmed this result. Hostility, anger and cynicism can even increase the risk of developing cancer and fatality.

In 2012 Erik Mortensen and his colleagues published a study in the Journal of Aging Research. The study showed that people with hostile personality traits generally perform less well in intelligence tests than positive people.

In the study the participants who were born in 1914 took intelligence and personality tests over a period of 30 years from the age of 50. The participants classified as hostile performed poorer in intelligence tests than other participants although their intelligence didn’t deteriorate more than that of the other participants in the final half of their lives.

Thus, the researchers did not find a higher age-related decline in intelligence in people with hostile personality traits.

Researchers have also found that depressive and anxious people are more prone to dementia than others.

Personality tests raise possibilities

When researchers discover that certain personality traits can affect our health, they use tests to evaluate how people score in different personality dimensions, such as:

  • Introvert or extrovert
  • Stable or unstable
  • Cynical, hostile and angry or friendly, optimistic and sociable.

“Just as it was established in the previous century how to carry out intelligence tests, we now have personality tests,” says Mortensen. “Of course it’s not possible to measure personality as precisely as intelligence, but some dimensions of personality are fairly certain and will always show. For instance introvert/extrovert and stable/unstable.”

Cynicism and paranoia cause stress

After the introduction of personality tests researchers have realised that some personality types are more prone to stress than others. According to Mortensen, this could explain why a character trait such as cynicism is associated with poor health.

“People who have a cynical, negative and slightly paranoid perception of others often get into conflicts. We know that conflicts and poor networks are stress factors. Stress is associated with various effects that are harmful to health,” he says. “For example, research indicates that the brain’s cognitive functions are harmed by stress and strain.”

But can this knowledge help people who’ve always been cynical or anxious -- is it even possible to change your personality?

“Many therapists claim that they can change people’s personality, but in my opinion they are making promises they can’t keep. Overall, personality is fairly stable, and fundamentally I don’t believe that it’s possible to change it,” says Mortensen. “But perhaps we can learn to tackle our personality traits in a more appropriate way.”

Self-image changes

Even if people think they change fundamentally as they gain life experience and perhaps work on tackling their traits it’s fairly unlikely that the basic character traits that have been there since childhood will have disappeared completely, says Mortensen.

“Lots of people believe that they have changed, but studies have been done where personality tests were carried out once a year and participants were asked at the same time whether they had changed,” he says.

The results showed that people haven’t changed -- even though they say they have.

“Self-image changes throughout life. Identity, roles and attitudes can change. But that isn’t the same as changes to the basic personality,” says Mortensen.

Self-awareness is the first step

However, if a person tends to be cynical and think negatively about other people it is possible to improve perceptions and relations to others and think more positively.

Mortensen says one option is to consider going to therapy in order to change any negative patterns of thought -- but adds that the first step to a more positive, balanced and healthy outlook is to become aware of any personality traits that could potentially be harmful to health.

“Just getting that knowledge will make you start to change your thought patterns. If you become aware that you have a tendency to get very angry and distrustful, then you’ll know that you should be careful not to react in certain ways in certain situations,” says Mortensen.

“In the US, courses were started where people could let out their anger when it became known that anger and hostility could constitute a risk to health,” he says, adding that he hasn’t seen the same interest in Denmark yet.

“Then there’s also the problem of telling people that they’re ill because of their personality,” he says. “You can’t put it like that: the connection isn’t overly strong and lots of other factors could play a role.”


Read the original article in Danish on

Translated by: Iben Gøtzsche Thiele

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