Links Between Best-Friendship Quality and Well-Being From Early Emerging Adulthood to Early Established Adulthood.

The aim of this study was to verify whether the links between features of best-friendship quality (intimacy, reliable alliance, conflict) and well-being indicators (self-esteem, loneliness) change from early emerging adulthood to early established adulthood. The moderating effect of gender and investment in romantic life on these links was examined as well. For the purpose, 346 individuals (58% women) completed questionnaires at age 20 and again at age 30. Multilevel analysis were performed for each well-being indicators separately. The results showed reliable alliance to be associated with both well-being indicators, and intimacy to be associated with loneliness. Age moderated the effect of intimacy on self-esteem, whereas investment in romantic life moderated the effect of reliable alliance. Finally, triple interactions emerged between conflict, gender and age in their associations with self-esteem and loneliness, underscoring particularities for men. These results underscore the most influential features of friendship quality for well-being.

Developmental changes in best friendship quality during emerging adulthood.

The purpose of this study was to examine change in four features of best friendship quality (intimacy, companionship, reliable alliance and conflict) from age 19 to 30 by gender and investment in romantic life. To this end, 363 participants (58% women) were asked about the quality of the relationship with their best friend and their level of investment in romantic life at ages 19, 20, 21, 22, 25 and 30. Latent growth curve analysis revealed a slight increase in reliable alliance and companionship and a slight decrease in intimacy in the early 20s followed by a steeper drop for these three features (quadratic trajectories), while conflict declined linearly. Women reported higher levels of intimacy and companionship and less conflict than men did at 19 years old. Also, their intimacy diminished throughout their 20s, slightly at first but more strongly thereafter. For men, it was lower early on and remained stable afterwards. Finally, investment in romantic life at age 19 was associated with change in intimacy levels shared with their best friend. This study confirms that features of best friendship quality change differently from one another during emerging adulthood and demonstrates the influence of gender and investment in romantic life on these changes.