Peer influence on West Point cadets' Civil War allegiances

• 成果类型: Article
• 署名作者: Guo, Yuchen; Jackson, Matthew O.; Jia, Ruixue
• 署名单位: Chinese University of Hong Kong; Stanford University; The Santa Fe Institute; University of California System; University of California San Diego; Centre for Economic Policy Research - UK; National Bureau of Economic Research
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.2529668123
• 发表日期: 2026-06-02
• 页码: e2529668123
• 关键词: Peer effects; peer influence; Civil war; west point; social networks; leadership; heroes

摘要

Do social networks and peer influence shape major life decisions in polarized settings? We explore this question by examining how peers influenced the allegiances of West Point cadets during the American Civil War. Leveraging quasi-random variations in the proportion of cadets from Free States, we analyze how cadets' decisions about which army to join depended on the composition of their peers. We have three main findings. First, there was a strong and significant peer effect: a higher proportion of classmates from Free States significantly increased the likelihood that cadets from Slave States joined the Union Army. Second, the peer effect varies with geography, most notably with the slave population share in cadets' home states or counties, and with cadets' own slave ownership in 1860. Third, peer effects were amplified by shared experiences such as having served together in the Mexican-American War, continuous military service, and belonging to the same cohort, suggesting that sustained interaction is important.