A recent study published in Personality & Individual Differences found that relationship satisfaction over a nine-year period is primarily influenced by one’s own personality traits, with Neuroticism having a negative effect and Conscientiousness a positive effect, while partner traits had negligible impact.
Kathrin Bach and colleagues investigated the long-term relationship between personality traits, specifically the Big Five (Neuroticism, Extraversion, Openness to Experience, Agreeableness, and Conscientiousness), and relationship satisfaction, motivated by prior findings linking personality to satisfaction in romantic relationships.
Previous research has highlighted that both actor effects (one’s own personality) and partner effects (the influence of the partner’s personality) play roles, but actor effects tend to be stronger. While Neuroticism, Conscientiousness, and Agreeableness have been shown to predict relationship satisfaction in cross-sectional studies, longitudinal data has been scarce, especially regarding long-term relationships.
The present study utilized data from the Panel Analysis of Intimate Relationships and Family Dynamics (Pairfam), a large-scale, 9-year longitudinal survey conducted in Germany. This dataset included three cohorts of individuals born between 1971 and 1993, with a total sample of 972 participants, or 486 heterosexual couples. The couples remained in relationships throughout the study period, providing a unique opportunity to assess the dynamics of personality and relationship satisfaction over time. The average age of male participants was 35, while for females, it was 32 at the start of the study.
Personality traits were measured using the short version of the Big Five Inventory (BFI-K) on a five-point Likert scale. Both partners rated their own personalities. Relationship satisfaction was measured using a single item drawn from the Relationship Assessment Scale, asking participants to rate their overall satisfaction with their relationship on a scale from 0 (very dissatisfied) to 10 (very satisfied). These measures were collected annually from both partners over nine waves, allowing the researchers to capture relationship satisfaction as a dynamic construct over a long period.
The results revealed that an individual’s own personality traits, rather than their partner’s traits, were the primary predictors of long-term relationship satisfaction. Neuroticism was found to have a consistently negative impact on satisfaction for both men and women, with higher levels of this trait predicting lower relationship satisfaction over time.
For men, the effect size was smaller compared to women, but still significant. In contrast, Conscientiousness had a positive effect on relationship satisfaction for both genders, meaning that more conscientious individuals—those who are organized, responsible, and reliable—tended to report higher satisfaction in their romantic relationships over the nine-year span.
Interestingly, the researchers found no significant effects for Agreeableness, a trait that had previously been linked to relationship satisfaction in cross-sectional studies. Additionally, Extraversion showed an unexpected negative association with relationship satisfaction for women, but not for men, suggesting that more extraverted women may experience lower satisfaction in long-term relationships, a finding that the authors suggested could be due to changing social and family dynamics over time.
One limitation was the dropout rate over the nine-year period, which may have led to a bias toward more satisfied couples remaining in the study, potentially limiting the generalizability of findings.
The study, “Relationship satisfaction and The Big Five – Utilizing longitudinal data covering 9 years”, was authored by Kathrin Bach, Marco Koch, and Frank M. Spinath.
