Changing or stable? The effects of adolescents' social media use on psychosocial functioning.

To better understand the effects of social media use on adolescents' psychosocial functioning, this study examined the temporal stability of social media effects across two separate 3-week experience sampling methodology (ESM) studies conducted 6 months apart in 2019 and 2020. Participants were 297 adolescents (M = 14.1 years, SD = 0.7, 58.9% girls; 41.1% boys; 0.1% other; 97% Dutch) who completed 126 momentary questionnaires on social media use, affective well-being, self-esteem, and friendship closeness in each of the two ESM studies. The effects of social media on psychosocial functioning had low rank-order stability (r = .05-.25). Findings indicated that the effects of social media use varied not only between individuals but also changed substantially within individuals over time.