This 14-day diary study among 200 youths (ages 10-14) examined within- and between-person associations of social media use (Instagram, TikTok, YouTube), subjective well-being, and upward social comparisons. Multilevel structural equation models revealed that social media use was linked to lower positive and higher negative self-worth daily, and upward social comparisons diminished well-being across all dimensions. Upward social comparisons partially mediated the effect of social media use on well-being at both levels. Youths' feelings of others being better off may explain inconsistencies in prior research.

Andrea Irmer, Florian Schmiedek