Do your school peers matter?

The effect of one's peers' academic achievement on one's own academic achievement tend to be modest and are often driven by a small number of peers.

• Students’ own characteristics are the most important predictors of their academic success, rather than students’ peers (Sallin and Balestra 2022)
• Peers exert most of their influence in closer, smaller groups, e.g. at the class-level rather than the cohort-level (Burke and Sass, 2013; Sallin and Balestra 2022), as seat-mates even more than classmates (Hong and Lee 2017), when their friendships last longer than a year (Patacchini et al 2017), and when they belong to the same racial group (Fruehwirth 2013).
  
• Most peers only have small impacts on the academic performance of others (Isphording and Zolitz 2022). The bulk of meaningful peer effects seem to come from low-achieving peers and peers with special needs (Bietenbeck, 2020; Balestra, Eugster, and Liebert 2022; Sallin and Balestra 2022)

Peers' personality traits and behavior appear to influence others more reliably than their academic performance. This may explain why selective high schools that admit students on the basis of test scores don't necessarily increase students' academic achievement. The following traits have been shown to improve peers' academic achievement:

• Peer persistence, which has approximately twice as large an effect as peer GPA (Golsteyn et al 2021)
• Peer conscientiousness (Shure 2021)
• Peer motivation, although peer motivation in elementary school does not affect longer-term educational success, likely because it does not change own motivation (Bietenbeck 2021)

Peers' personality can also influence others' personality directly.

• Students become more conscientious when assigned to conscientious peers, more open-minded when assigned to open-minded peers, and more competitive when assigned to competitive peers. The effects on conscientiousness and competitiveness persist for up to three years. No spillovers were detected on extraversion, agreeableness, or neuroticism (Shan and Zolitz 2022).

Finally, behavioral peer effects can occur outside the classroom.

• Informal social interactions on the bus are likely to have greater effects on behavioral rather than academic outcomes, appear more meaningful in adolescence than in childhood, and can be highly local within a broader group (Lenard and Silliman 2022)

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