Exploring the mechanistic pathways of how social network influences social norms in adolescent smoking prevention interventions

Abstract

We know little about how smoking prevention interventions might leverage social network structures to enhance protective social norms. In this study we combined statistical and network science methods to explore how social networks influence social norms related to adolescent smoking in school-specific settings in Northern Ireland and Colombia. Pupils (12-15 years old) participated in two smoking prevention interventions in both countries (n = 1344). A Latent Transition Analysis identified three groups characterized by descriptive and injunctive norms towards smoking. We employed a Separable Temporal Random Graph Model to analyze homophily in social norms and conducted a descriptive analysis of the changes in the students' and their friends' social norms over time to account for social influence. The results showed that students were more likely to be friends with others who had social norms against smoking. However, students with social norms favorable towards smoking had more friends with similar views than the students with perceived norms against smoking, underlining the importance of network thresholds. Our results support the notation that the ASSIST intervention takes advantage of friendship networks to leverage greater change in the students' smoking social norms than the Dead Cool intervention, reiterating that social norms are subject to social influence.

Figure 1

Possible changes in the student social norms from baseline to follow-up: change social norms to favorable towards smoking, change social norms to against towards smoking, maintain social norms favorable towards smoking, or maintain social norms against smoking.

Figure 2

Friendship networks, sorted by setting and intervention. Nodes: students. Edges: friendship nominations at baseline. For nodes: color is the corresponding change in social norm, size is the in-degree.

Figure 3

The proportion of friends that were maintained from baseline to follow-up by an ego (i.e. the individual participant) that changed their social norms, according to the change in the social norms of the ego. Each caption represents the proportion of ego’s friends that changed their social norms, differentiating by setting and intervention, according to the change of the ego’s social norms. Green represents students who maintained social norms against smoking, orange represents students who maintained social norms favorable towards smoking, yellow represents students who changed social norms to against smoking, and blue represents students who changed social norms to favorable towards smoking. For example, (a) shows the proportion of friends that changed or maintained their social norms for the egos that maintained their social norms favorable towards smoking.