Background

Marijuana is the most frequently used illicit drug among college students, and there is a need to understand the social processes that contribute to young adults’ marijuana use. Substance use behaviors tend to be more similar (homophilous) among individuals with social ties to one another. However, little is known about whether marijuana use homophily within young adult relationships is due to social selection (seeking out ties with similar marijuana use to one’s own) or social influence (adopting similar marijuana use behaviors as one’s ties), or both. Methods: Students (N = 1,489; 54.6% female; M_age = 18.6 years) at one University completed online surveys in their first three semesters of college. Surveys assessed participant characteristics, marijuana use, and ties to up to 10 other students in the whole (sociocentric) network of first-year college students. Stochastic-actor oriented models (SAOMs) were used to analyze the co-evolution of marijuana use and social ties over time. Results: Participants were more likely to select peers with similar past 30-day marijuana use as themselves. Concurrently, students’ past 30-day marijuana use became more similar to their peers’ use over time. Discussion: Evidence for selection and influence effects were highly significant after controlling for network structure and other covariates indicating these processes may work in tandem to increase marijuana use homophily over the first year of college. This highlights the importance of relationships made early in the first-year of college, as these initial peer ties are likely to reinforce marijuana use behaviors that occur within these relationships.

中文翻译：

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在一年级大学生的完整网络中使用大麻的同伴选择和影响

背景

大麻是大学生中最常使用的非法药物，有必要了解导致年轻人吸食大麻的社会过程。物质使用行为在彼此具有社会联系的个体之间往往更相似（同性）。然而，关于在年轻成人关系中吸食大麻的同质性是由于社会选择（寻找与自己吸食大麻相似的关系）还是社会影响（将吸食相似行为作为自己的关系），或两者兼而有之，我们知之甚少。方法：学生（N = 1,489；54.6% 为女性；M_岁 = 18.6 岁）在一所大学完成了大学前三个学期的在线调查。调查评估了参与者的特征、大麻使用情况以及与整个（以社会为中心的）大学一年级学生网络中多达 10 名其他学生的联系。随机参与者导向模型 (SAOM) 用于分析大麻使用和社会关系随时间的共同演变。结果：参与者更有可能选择过去 30 天吸食大麻的同龄人与自己相似。同时，随着时间的推移，学生过去 30 天吸食大麻的情况与同龄人的吸食情况越来越相似。讨论：在控制网络结构和其他协变量后，选择和影响效应的证据非常显着，表明这些过程可能协同工作，以增加大学第一年的大麻使用同质性。