Personality traits are a robust predictor of loneliness, according to the first large-scale systematic review of studies of the topic. The new research, published in the European Journal of Personality, could help to identify those most at risk of loneliness.

“During my undergraduate in psychology, I became curious about what makes people the way they are, why people differ, and which social consequences these individual differences have,” explained Susanne Buecker (@BueckerSusanne), a PhD candidate at Ruhr University Bochum in Germany and the corresponding author of the new study.

“In my PhD, I therefore focused on the nature and development of loneliness. Loneliness is described as the subjective perception of a discrepancy between the desired and the actual social relationships in terms of companionship, connectedness, or intimacy. Most people think of old age, the loss of a partner, health issues or low socioeconomic status when it comes to risk factors for loneliness. In my research, I show that personality traits also seem to be relevant.”

The researchers conducted a meta-analysis of 113 published and unpublished studies that examined the relationships between the Big Five personality traits — openness to experience, conscientiousness, extraversion, agreeableness, and neuroticism — and loneliness. The studies included 93,668 participants in total.

Buecker and her colleagues found that lonely people tended to be more introverted and neurotic and somewhat less agreeable and conscientious than less lonely people on average.

“This meta-analysis aggregated studies including measures of broader personality traits and loneliness that were conducted over the last 38 years. We found that extraversion (being sociable, assertive, and energetic) was negatively related to loneliness and neuroticism (being moody, nervous, and touchy) was positively related to loneliness,” she told PsyPost.

“But to a lesser extent also agreeableness (being kind, considerate, and generous) and conscientiousness (being organized, responsible, and efficient) were negatively related to loneliness. Openness to experiences did not seem to play an important role in the context of loneliness.”

The researchers also found that being introverted was more strongly related to social loneliness (having a fewer number of friends) than to emotional loneliness (the perceived absence of close attachments.)

The direction of the relationship between personality and loneliness, however, is still unclear.

“Whereas this meta-analysis describes the nature and magnitude of the relations between loneliness and broader personality traits, we do not yet know whether our personality affects loneliness or whether loneliness affects our personality,” Buecker explained.

“Previous research suggests that both directions of the effects are plausible. Personality might be related to loneliness because personality-related behaviors (e.g., attending social events or not), thoughts (e.g., negatively biased perception of other people) and feelings (e.g., being anxious) are likely to have an impact on how we see others, how we are seen by others, how we interact with them, and how we interpret and cope with social interaction outcomes.”

“This, in turn, may impact our social relationships and, consequently, our experience of loneliness. But there is also some evidence that loneliness predicts personality traits many years later. To draw sound conclusions on the direction of the effect of personality and loneliness, we would need experimental studies,” Buecker said.

Loneliness appears to be a fundamental part of the human condition, and can have serious consequences. Research has found that loneliness is a major health risk that can increase the risk of premature death by 14 percent.

“Understanding how broader personality traits and loneliness are related is not only of interest from a theoretical perspective, but can also have practical implications, for example by informing prevention and intervention strategies against loneliness,” Buecker said.

“Loneliness can occur across diagnostic boundaries. The knowledge of the associations between personality traits and loneliness can point out personality-typical behaviors related to loneliness such as introverted and emotionally unstable states that could be considered in therapeutic settings.”