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Being healthy is typically regarded as an important goal in life. Correspondingly, many (potential) antecedents and correlates of health have been investigated. For instance, research has shown that environmental factors, such as climate change or social inequality, can negatively affect health.

Next to environmental factors, individual differences in cognitive abilities or socioeconomic status have been associated with health. Indeed, Greek and Roman philosophers, such as Hippocrates or Galen, explored individual differences in the inclination toward good health. More recently, there has been an increase in interest in the relations of personality characteristics with health, often referring to broad, basic personality dimensions.

Basic personality dimensions

A large body of research on personality traits rests on the assumption that personality traits are engrained in the language that we use, which is called the lexical approach to personality. Accordingly, individuals use different adjectives to describe the behaviors, tendencies, and characteristics of themselves and others, and these adjectives can then be seen as indicators of individual differences and, in turn, people’s personality traits. Following the collection of many such descriptive data across languages (countries, cultures), researchers have created comprehensive taxonomies of personality traits, summarizing and structuring the variety of many different personality traits in a few broad, basic dimensions.

Whereas the most widely known personality taxonomy is the Big Five/Five-Factor approach, research over the last two decades has suggested that a taxonomy comprising six basic dimensions might structure personality traits better. This alternative model is called the HEXACO model. It includes the broad dimensions of honesty-humility, emotionality, extraversion, agreeableness vs. anger, conscientiousness, and openness to experience.

Meta-analysis on the relations between HEXACO dimensions and health

Recently, led by Jan Luca Pletzer and Isabel Thielmann, we summarized the findings of previous studies linking the HEXACO dimensions with various health outcomes in a meta-analysis. In line with previous research, we grouped these health outcomes into three broad health categories: Mental health (reflecting cognitive, emotional, and social well-being in particular), health behavior (reflecting engagement in health-promoting or health-deteriorating activities in particular), and physical health (reflecting the fitness of one’s body in particular). Based on data from 276 studies with more than 92,000 participants overall, we found that the personality dimensions combined were particularly associated with mental health, somewhat associated with health behavior, but not really associated with physical health. This finding mirrors earlier findings for the Big Five dimensions. But let’s look at the results across these three categories in some more detail.

Mental health

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The key finding for mental health was that it showed strong links with Extraversion. More precisely, people with higher levels of Extraversion tend to experience many positive emotions, be resilient, and have high levels of self-esteem. They are also much less likely to experience symptoms of burnout or depression compared to people with low levels in this dimension. In addition, we found that higher levels of agreeableness vs. anger, conscientiousness, and honesty-humility, as well as lower levels of emotionality, were beneficial for mental health.

Health behavior

Having higher levels of honesty-humility, conscientiousness, as well as agreeableness vs. anger was related to engaging in healthy behavior. Individuals with respective personality characteristics were found to be less likely to be aggressive, engage in risky behavior, smoke, and drink alcohol. Interestingly, Extraversion was not strongly associated with health behavior: People with higher levels in this domain generally enjoy social activities, and these social activities can be both health-promoting (e.g., exercising together) and health-deteriorating (e.g., drinking together), largely canceling each other out (in a meta-analysis).

Physical health

In contrast to mental health and health behavior, the associations of the HEXACO domains with physical health were largely weak and non-significant. Only two domains were significantly, yet weakly, related to physical health. Emotionality was negatively related to physical health, mostly because individuals with higher levels in this domain tend to be physically weaker. This suggests that individuals who are prone to be dependent on others and who tend to experience emotional instability may be more likely to experience physical health issues. Conversely, conscientiousness exhibited a small positive correlation with physical health because people with higher levels in this domain scored higher on measures of physical strength. Importantly, though, more research that links the HEXACO domains to diagnosed physical diseases and other measures of physical fitness needs to be conducted.

Source: Image by Steve Buissinne from Pixabay

Comparing HEXACO and Big Five/Five-Factor dimensions

We also examined whether Honesty-Humility, the domain that represents the most obvious difference between the HEXACO and the Big Five/Five-Factor approach, related to the health outcomes over and above the Big Five domains. Past research has found this to be the case, especially for antisocial, counterproductive, and prosocial behaviors. In the health domain, honesty-humility did explain the additional variance, especially for some health behaviors, such as aggression or gambling. At the same time, it did not do so for most mental health and physical health outcomes. When comparing relations with specific health outcomes across the Big Five and HEXACO models, the general conclusion could be that both models are advantageous in exhibiting stronger associations with some outcomes but not for others. As such, the choice of using the Big Five or the HEXACO model when aiming to predict health could be outcome-dependent.

What can we learn from this?

Personality is an important predictor of (mental) health. For mental health, we found particularly strong links with Extraversion but also links with higher levels of conscientiousness, agreeableness vs. anger, and honesty-humility, as well as lower levels of emotionality. Understanding these relations can have far-reaching implications for healthcare professionals, policymakers, and individuals. By recognizing the importance of personality for mental health and health behavior, interventions might be tailored to certain individuals to promote overall well-being. For example, a review showed that interventions specifically tailored to recipients' personality traits could substantially reduce substance use and misuse.

Crucially, our findings do not mean that individuals with traits that incline them to be less healthy are also automatically less healthy. Many other factors can affect how healthy someone is, and certain situational factors, including social or professional support, can amplify or counteract relations of personality traits with health.