Objective: This article examined the contribution of selection and influence processes in smoking behavior similarity among friends, and changes in these processes during early and mid adolescence.
Design: Data from 1886 Dutch high school students in the control group of the European Smoking prevention Framework Approach (ESFA) study were used. Changes in selection and influence were examined during three successive waves using structural equation modeling.
Main outcome measures: Smoking behavior of adolescents, best friends, parents, and siblings.
Results: Most support was found for selection of reciprocal (p(wave1,2,3) < 0.01) and nonreciprocal friends (p(wave1,2) < 0.01; p(wave3) = 0.25), although these effects decreased over time. Support for influence was only found among nonreciprocal (desired) friends during the last wave (p(wave3) < 0.01). Adolescents were influenced by their parents (p(wave2) < 0.01; p(wave1,3) > 0.05) and siblings (p(wave1,2) < 0.01; p(wave3) = 0.16), but influence diminished over time.
Conclusion: Smoking-based selection processes decreased over time while the influence of friends increased. Smoking prevention programs should focus on the structure of peer environments besides promoting social influence skills. During early adolescence parents and siblings should be targeted, while during mid adolescence, the focus should shift toward the adolescents and their dynamic peer environment.
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