Your personality can invite loneliness, and loneliness can shape your personality

It's often assumed that personality is largely fixed, like your height or shoe size. But a better analogy might be between personality and body weight. After all, like an expanding waist span, there's evidence that personality changes as we get older. And just as we can strive to lose weight, there's evidence we can intentionally change our personalities.

Now Marcus Mund and Franz Neyer at the Institute of Psychology at Friedrich Schiller University, Jena in Germany have explored two factors – loneliness and feelings of health – that influence the way people's personality shifts in early to mid-life, and in turn how their personality affects those very same factors. In short, it appears our personality affects the likelihood that we'll become more lonely (and feel less well) as we get older, but also that being lonely (and feeling less healthy) shapes our personality, potentially setting up a vicious circle of isolation.

The researchers measured the personality traits, loneliness and subjective health of 661 healthy young adults (average age 24) in 1995 and then tracked down 271 of them in 2010 and asked them the same questions (by which time the average age of the sample was 40). To measure subjective health, participants simply responded to the question "How is your health in general?" on a 5-point scale from "very good" to "bad".

Over the fifteen-year span of the study, the participants on average grew more lonely and felt less healthy. Meanwhile, their scores on the personality traits of neuroticism and extraversion decreased over time, while their scores on agreeableness and conscientiousness increased (the other main factor of personality "openness to experience" was not measured in this study).

But where people ended up in mid-life also depended to some extent on the kind of person they were in their youth. That is to say, the personality measures taken in the participants' youth correlated with their health and loneliness scores in mid-life; also the loneliness and health measures in youth correlated with personality in mid-life. Specifically, people who scored higher in neuroticism in their twenties tended to be lonelier in mid-life; and people who felt less well and lonelier in their twenties tended in mid-life to score higher on neuroticism, but lower on extraversion and conscientiousness.

More intriguing still is the two-way dynamics between evolving personality factors on the one hand and changes to loneliness and subjective health on the other. For example, greater loneliness in youth went hand in hand with slower decreases in neuroticism with age, and slower increases in conscientiousness. In other words, feeling lonely when young appears to shape the course of personality development in an unfavourable way. And the reverse is true: for example, those participants who were less neurotic in their twenties and who grew more rapidly in extraversion with age tended to enjoy slower declines in health and slower increases in loneliness with age.

How might loneliness, or feeling less well, shape the way a person's personality develops? Mund and Neyer speculate that perhaps it is through physical and social inactivity. Who we are is based partly on who we mix with and the part we play in our social relationships. People who lack this connection (and those with an initial anxious and introvert personality are more vulnerable to this state of affairs) are likely to miss out on these experiences, further shaping their personality in directions that lead to more isolation.

This study has some serious limitations: a lot of the initial participants dropped out; it's a shame there were only two time points; and we know nothing of the participants' experiences in the fifteen year span of the study – such experiences could simultaneously shape personality, loneliness and health, explaining their correlation over time. Nonetheless, this is largely unexplored terrain and the study offers some tantalising glimpses of the dynamic two-way interactions between personality and loneliness and health.

Further reading

Mund, M., & Neyer, F. (2015). The Winding Paths of the Lonesome Cowboy: Evidence for Mutual Influences between Personality, Subjective Health, and Loneliness Journal of Personality DOI: 10.1111/jopy.12188