The Co-development of Extraversion and Friendships: Bonding and Behavioral Mechanisms in Friendship Networks

Abstract

Empirical evidence suggests that people select friends whose extraversion is similar to their own (selection effects). However, little is known about whether friends influence extraversion development (influence effects) and about the interaction mechanisms that underlie friendship selection and influence effects. We examined whether selection and influence effects explain similarity in extraversion between friends in two independent samples. Similarity in extraversion predicted a higher likelihood of friendship selection across four years in Sample 1 (n = 1,698; Mage = 22.72, SD = 2.99; 49% female) and across a period of 16 weeks in Sample 2 (n = 131; Mage = 21.34, SD = 3.95; 77% female). Friends’ extraversion predicted increases in young adults’ extraversion in both samples. In Sample 2, we examined the interaction mechanisms underlying these selection and influence effects by combining event-based experience-sampling network dynamics with diary data on friendship network and extraversion dynamics. Findings showed that (a) similarity in extraversion predicted positive interaction quality changes and (b) positive interaction quality predicted friendship selection (bonding mechanism). In the same sample, (I) friends’ extraversion predicted friends’ sociable behavior changes, (II) friends’ sociable behavior predicted young adults’ sociable behavior changes, and (III) young adults’ sociable behavior predicted extraversion changes (behavioral mimicry mechanism). These findings provide unique insight into interaction mechanisms underlying longitudinal links between friendships and extraversion.

Explaining the Longitudinal Interplay of Personality and Social Relationships in the Laboratory and in the Field: The PILS and the CONNECT Study

“…; e.g., [58,165,166]) Do such potential changes gradually evolve (e.g., based on certain gradually changing behavioral and mental state dynamics) or do they quickly become apparent given specific events (e.g., characterized by specific novel behavioral or mental states; e.g., [53,167])? Based on intensive and longitudinal approaches that capture the expressions of personality and social relationships at multiple time points and perhaps more intensively during the initial phases of relationship emergence, stabilization, and change can be modeled, and the behavioral and interpersonal processes underlying these dynamics can be unraveled (e.g., [168,169]).…”

“…In We provide open material with detailed descriptions of PILS and CONNECT in the Open Science Framework (PILS: osf.io/q5zwp [85]; CONNECT: osf.io/2pmcr [86]). By providing open code in our publications on PILS and CONNECT data, we have already made (i.e., [78,[158][159][160][161]163,[168][169][170][171][172][173][174][175][176]179,180,182]) and will continue to make public all analytical codes needed to comprehend and reproduce the results presented in our articles (e.g., R codes, Mplus codes; see osf.io/5tw8b/ for this paper). Herewith, we also provide open data for the all descriptive and exemplary analyses (also see osf.io/zj38h/) to actually offer other researchers the opportunity to reproduce the published results with the provided analytical code.…”