The hypothesis that personality and health are linked is nothing new. The Romans and Greeks thought there was a relationship, and present-day investigators are looking much more closely at that connection.
In the 20th century, the emergence and evolution of the five-factor model of personality (ie, extraversion, agreeableness, conscientiousness, emotional stability, and intellect/openness) advanced the research into personality and health. This model is popularly referred to as the “Big 5.”
Health and personality may exert bidirectional causality, with each having an effect on the other. Let’s take a closer look at the evidence supporting this relationship.
Of all the Big 5 traits, data best supports the dynamic between conscientiousness and health, according to the Personality and Health entry in the Oxford Research Encyclopedias. Conscientious people exhibit decreased morbidity and mortality, which could be due to better health behaviors and stronger social ties, as well as less stress.
In terms of biomarkers, those who are less conscientious tend to harbor higher levels of leptin, indicating leptin resistance and a predisposition to weight gain. These types of people also tend to display worse lipid profiles. Lower conscientiousness was also linked to worsened nighttime blood pressure patterns. Those who were less conscientious also exhibited heightened concentrations of inflammatory markers, such as IL-6 and CRP.
Neuroticism on its own is linked to maladaptive health behaviors, death, and disease. “Healthy neuroticism,” however, may be linked to positive health behaviors, according to the results of a coordinated analysis published in Collabra: Psychology.
Healthy neuroticism is defined as high neuroticism paired with high conscientiousness. In the current coordinated analysis, findings indicated that this pairing was linked to decreased smoking and increased exercise levels, but not to levels of alcohol intake. The authors suggested that these results may apply across a wide range of populations.
On a related note, the investigators found that healthy neuroticism was not linked to morbidity or mortality in two other associated studies.
At some point, you’ve likely heard the term “Type A” used to refer to acquaintances, colleagues, family members, friends, or yourself. Type A personality refers to action-oriented tendencies and has been historically tied to heart disease in middle-aged and older adults. Type A personality is termed “coronary-prone behavior,” and it is characterized by a strong drive to reach goals, aggressiveness, adherence to rigid deadlines, competitiveness, and more. In epidemiologic studies, a strong association between Type A personality and cardiovascular disease has been shown.
According to the authors of a study published in the International Journal of Behavioral Medicine, various mechanisms may underlie the association between Type A personality and heart disease, including increased cigarette smoking and alcohol intake, as well as anger and associated hemodynamic instability.
One area of personality and health psychology that has received much interest is Type C—or cancer-prone—personality. Type C can refer to many characteristics, including passivity, focus on others, anger-repression, helplessness, patience, agreeableness, and self-sacrifice.
In a recent study published in Frontiers in Psychology, investigators boiled down Type C personality to two main factors for which they found internal consistency: submissiveness and restricted affectivity. In other words, the various other suggested traits associated with Type C may bear little significance.
“In research aimed at finding the personality determinants of somatic diseases, Type C personality has been proposed and treated as a significant predictor of the incidence of cancer,” wrote the authors. “The analysis of the available literature on Type C has revealed a number of characteristics postulated as elements of Type C, which were not always internally consistent and did not form a precisely defined whole. This might have been one of the causes behind the divergence, reported in the literature, in research results concerning the significance of Type C personality in predicting cancers.”
Importantly, the researchers suggested that their research is the first in clarifying what Type C personality actually is.
In a study published in the Journal of Black Psychology, investigators suggested ways in which personality can be paired with interventions to improve health. Of note, researchers were investigating the relationship between the Big 5 and physical functioning in a population-based sample of Black adults.
The authors suggested that “interventions targeting individuals’ personality and social skills may help people become more aware of available social support and perceive their support more favorably. Interventions could train participants in increasing and diversifying their social network, teach them how to elicit assistance from their network, provide resources for forming more links with their community, and assist them in learning to accept help when offered.”
Interventions targeting personality could also help with conflict avoidance and encourage interdependence. Targeting higher conscientiousness and extraversion, as well as lower levels of neuroticism, could help those who have diminished social support.