An actor-based model of social network influence on adolescent body size, screen time, and playing sports. Journal Article


Authors: Shoham, D. A.; Tong, L.; Lamberson, P. J.; Auchincloss, A. H.; Zhang, J; Dugas, L; Kaufman, J. S.; Cooper, R. S.; Luke, A
Article Title: An actor-based model of social network influence on adolescent body size, screen time, and playing sports.
Abstract: Recent studies suggest that obesity may be "contagious" between individuals in social networks. Social contagion (influence), however, may not be identifiable using traditional statistical approaches because they cannot distinguish contagion from homophily (the propensity for individuals to select friends who are similar to themselves) or from shared environmental influences. In this paper, we apply the stochastic actor-based model (SABM) framework developed by Snijders and colleagues to data on adolescent body mass index (BMI), screen time, and playing active sports. Our primary hypothesis was that social influences on adolescent body size and related behaviors are independent of friend selection. Employing the SABM, we simultaneously modeled network dynamics (friendship selection based on homophily and structural characteristics of the network) and social influence. We focused on the 2 largest schools in the National Longitudinal Study of Adolescent Health (Add Health) and held the school environment constant by examining the 2 school networks separately (N=624 and 1151). Results show support in both schools for homophily on BMI, but also for social influence on BMI. There was no evidence of homophily on screen time in either school, while only one of the schools showed homophily on playing active sports. There was, however, evidence of social influence on screen time in one of the schools, and playing active sports in both schools. These results suggest that both homophily and social influence are important in understanding patterns of adolescent obesity. Intervention efforts should take into consideration peers' influence on one another, rather than treating "high risk" adolescents in isolation.
Journal Title: PloS one
Volume: 7
Issue: 6
ISSN: 1932-6203; 1932-6203
Publisher: Unknown  
Journal Place: United States
Date Published: 2012
Start Page: e39795
Language: English
DOI/URL:
Notes: ID: 12623; Status: MEDLINE; Publishing Model: Journal available in: Print-Electronic Citation processed from: Internet; NLM Journal Code: 101285081; Other ID: Source: NLM. PMC3387251; Grant Number: P01-HD31921 (United States NICHD NIH HHS), U01-HD061978 (United States NICHD NIH HHS)