A personality test isn't usually part of a regular physical. Along with being asked to turn your head and cough, though, questions about how risk-averse you are might become a regular part of doctor's visits, if a new study is anything to go by.
The study, published in the journal Psychoneuroendocrinology — which like you, I read regularly — was conducted by a team led by Dr Kavita Vedhara. Dr Vedhara and her co-authors asked 121 people questions about their personalities, and tested their blood for the expression of genes related to inflammation.
The personality trait labelled "extroversion" was associated with increased inflammatory response, meaning that people who scored higher for openness and being a "people person", and who said they enjoyed activities in groups, were more likely to show inflammatory gene expression.
By contrast, people who scored highly for conscientiousness showed less inflammatory gene expression. Conscientious individuals are more likely to identify with statements like: "I am seen as "reflective" or "reserved"; "I feel comfortable being alone and like things I can do on my own"; and "I prefer to know just a few people well", and are less likely to take risks.
What the study doesn't show is why that could be the case.
The authors suggest that the personality could be the result of the genes — that people with weak immune systems become introverted in order to avoid exposure to pathogens which they're less well-equipped to flight off than their extroverted opposite numbers. The same increased subjective risk could cause them to become more conscientious.
It's equally possible the personality affects gene expression: people who live more gregarious,extroverted lives might encounter more pathogens,strengthening their immune systems and triggering the expression of genes for inflammatory responses.
The study's authors caution against introducing personality tests as a blanket roll-out to every standard doctor's visit. But Dr Vedhara does think that treatment plans that include looking at a patient's psychological profile as well as their physical symptoms could hold out hope for a more effective, more individualized medicine.
In particular, she observes that "if you're confronted by a chronic condition", like diabetes or heart disease, "you may have underlying beliefs about your condition which might influence your underlying physiology and your ability to recover and manage your disease, [and] you may well have an orientation which makes you more or less likely to exercise" — and an assessment that includes those factors may be more accurate and effective. In particular, doctors might treat chronic conditions better if they have access to accompanying psychological information.
"Most areas of medical intervention work quite well," said Dr Vedhara, "but I think that we’re on the brink of seeing a future where we use psychological interventions and behavioral interventions to maximize their efficacy."
Could Your Personality Even Affect How Long You Live?
As well as gauging the effectiveness of your immune system, your personality might also hold the key to knowing how long you're likely to live.
That's the position put forward by Joshua Jackson, a psychology professor at Washington University. Professor Jackson sees understanding personality as an important way to improve physical health.
In a recent study, led by Professor Jackson, the team examined how your friends' assessment of your personality might affect how long you were likely to live.
Professor Jackson suggested that the results could be caused by behaviours associated with those character traits. For example, "conscientious people tend to eat their vegetables and exercise", and would also typically avoid unnecessarily risky behaviours like driving without a seatbelt. He summarized: "They just seem to live a nice, tidy, buttoned-up life, which helps them live longer."
Open individuals, meanwhile, "are not necessarily set in their ways, they’re able to change, they’re open to new experiences". That could mean being more willing to change their minds about how to live, in line with new discoveries or the advice of health professionals. However, openness may also be associated with the propensity to seek out mentally challenging activities, such as crossword puzzles or challenging games like chess, and this type of activity is associated with greater mental agility and reduced cognitive decline in old age.
Well, some of that may have to do with the fact that Dr Jackson's team was using data from the 1930s, in order to have a population that could be tracked for natural mortality over a range of different times. As a result, the descriptions need to be interpreted in the light of the basically sexist social mores of the 1930s. In particular, the descriptors of women might be skewed by the fact that "high levels of peer-rated emotional stability and agreeableness predict mortality because they largely assess positive characteristics indicative of a supportive and easy-going wife, such as that described in the social theory of the time." In both men and women, it may be that simply being considered likeable is conducive to longevity, and the two different, gendered descriptions are simply ways of saying "good person" in a sexist society.
More worryingly, and less fairly, it's also possible that reality itself might be sexist and "that personality within women has a less robust relationship with health and longevity", in the words of Dr Jackson.
While it's unlikely that personality tests and Rorschach blots are going to find their way into every doctor's waiting room, it's great to see the beginnings of a truly person-centered, holistic approach to medicine that's also solidly based in science.