Peer Influence Via Instagram: Effects on Brain and Behavior in Adolescence and Young Adulthood.
Level 4 - case-series / case-control
Cross-sectional laboratory fMRI experimental study (graded by design analogy)
PubMed 28612930 · doi:10.1111/cdev.12838
What was done
Sixty-one high school and college students aged 13–21 viewed their own and others' Instagram photographs while undergoing functional Magnetic Resonance Imaging (fMRI). The study assessed behavioral liking decisions and brain activation patterns in response to photographs displaying manipulated peer endorsement (many vs. few Likes) and content types (risk-taking vs. nonrisky photographs).
What was found
The abstract reports no exact numbers, percentages, or effect sizes. Directionally, participants were more likely to Like photographs displayed with many versus few Likes. Viewing popular photographs elicited greater activity in brain regions including the nucleus accumbens (NAcc). NAcc responsivity increased with age among high school students, but not college students. Furthermore, high school students, but not college students, demonstrated decreased activation in brain regions implicated in cognitive control when viewing risk-taking versus nonrisky photographs.
Why it matters
This study provides mechanistic evidence that digital peer metrics engage neural reward processing in youth. It identifies age-dependent differences, suggesting adolescents may experience lower cognitive control engagement when encountering peer-endorsed risky content compared to young adults.
Limits
No quantitative effect sizes, test statistics, or confidence intervals are reported in the abstract. The sample size is small (N = 61) and divided between two distinct developmental groups. The laboratory fMRI paradigm cannot fully reproduce real-world, dynamic social media engagement, and longitudinal behavioral outcomes were not assessed.
Cited by
- supports Digital media engages the same brain reward pathways as drugs and alcohol.