Emotional Closeness With Friends Is Associated With Sociodemographic Similarity and Personality Traits

The Similarity–Attraction hypothesis suggests that people tend to like others who are more similar to them. Friends tend to resemble each other, but it is unknown whether the greater resemblance leads to greater friendship quality. This association might also depend on the person’s personality traits, which have been associated with differences in friendship patterns. The current study examined whether similarity in four sociodemographic characteristics (age, sex, marital status, and parenthood status) between friends, and the personality traits of the participant (extraversion, emotional stability, agreeableness, conscientiousness, and openness to experience), were associated with higher emotional closeness with friends, as reported by the participant. Data were from the German Panel Analysis of Intimate Relationships and Family Dynamics (pairfam; n = 7,699 participants who reported relationship information on 44,199 of their friends across two study waves). We used fixed-effect multilevel regression models to examine associations between sociodemographic similarity and emotional closeness based on within-participant variation across different friends of the participant. Higher sociodemographic similarity was associated with higher emotional closeness, more strongly for women than men. Higher extraversion, agreeableness, conscientiousness, and openness to experience of the participant were associated with higher emotional closeness, and the associations of conscientiousness and openness to experience were amplified by higher friend similarity. Most of these associations between personality and friendship emotional closeness were small in magnitude. The findings extend the Similarity–Attraction hypothesis by showing that friend similarity is related to higher emotional closeness.