s ome r esults f rom Scottish d ata

1. some results from Scottish data Topicsmoking behaviour and friendship Probleminfluence and/or selection Theorydrifting smoke rings (Pearson, West, Michell) Datathree wave panel ’95’96’97, school year group, age 13-16 MethodSIENA modelling

2. some results from Scottish data • skip through to Theory • Smoke rings (Pearson & Michell 2000) and • Drifting smoke rings (Pearson & West 2003) • Group position determines smoking behaviour (influence effects) • peripherals most unstable? (P&M) • peer pressure strongest in groups? (O&D) • isolates most stable smokers? (E&B) • Smoking behaviour determines group position (selection effects) • peripheral smoking rewarded by acceptance • in a smoking group? (P&W) • group smoking punished by rejection in a • non-smoking group? (O&D) • isolate smoking breeds further isolation? (P&W)

3. some results from Scottish data • Modelling • (A) group position as local cohesion, • e.g., reciprocity: group member isembedded in many reciprocal dyads isolate is not part of any reciprocal dyad peripheral is attached to others, but not reciprocated Problem: reduction to one explanatory dimension

4. some results from Scottish data • Modelling • (A) include effects of • reciprocity • similarity • similarity × reciprocity • into the objective functions for network • and/or behavioural change of actor i.

5. some results from Scottish data • Modelling • (A) include effects of • reciprocity • similarity • similarity × reciprocity • into the objective functions for network • and/or behavioural change of actor i. similarity

6. some results from Scottish data Modelling (B)group position as specific configuration of the neighbourhood group memberbelongs to clique of three isolate has no incoming ties peripheral is unilaterally attached to group Problem: reduction of ‘explanatory data’ , loss of statistical power

7. some results from Scottish data • Modelling • (B)include effects of • isolate status • group status • peripheral status • similarity • group status × similarity • peripheral status × similarity • into the objective functions for network • and/or behavioural change of actor i.

8. some results from Scottish data • Results • (A) SIENA “target statistic” descriptives • Average statistic observed per actor and time interval. Second column: expectations under independence.

9. some results from Scottish data • Results • (A) SIENA parameter estimates: basis model

10. some results from Scottish data • Results • (A) SIENA parameter estimates: basis model

11. some results from Scottish data • Results • (A) SIENA parameter estimates: basis model

12. some results from Scottish data • Results • (A) SIENA parameter estimates: basis model

13. some results from Scottish data • Results • (A) SIENA estimatesextended models: • similarity × reciprocity in network model • (all other parameters barely change)

14. some results from Scottish data • Results • (A) SIENA estimatesextended models: • similarity × reciprocity in behavioural model

15. some results from Scottish data • Results • (A) SIENA estimatesextended models: • same model with prev. estimates as starting value

16. some results from Scottish data • Results • (B) SIENA “target statistic” descriptives • Average statistic observed per actor and time interval.

17. some results from Scottish data • Results • (B) SIENA parameter estimates • group position in behavioural model

18. some results from Scottish data • Results • (B) SIENA parameter estimates • same without peripheral statuseffect

19. some results from Scottish data • Influence question • Are peripherals most unstable? • Yes… • influence is strongest in asymmetric relationships • but… • results do not strictly distinguish between peripherals and isolates. • If a peripheral is attached to a homogeneous group, the asymmetric influence effect can be decisive.

20. some results from Scottish data • Influence question • Is peer pressure strongest in groups? • Definitely not. • reciprocity ‘cools down’ the similarity effect, influence is strongest in asymmetric relationshipss • (effect not shown here:) there is a non-significant preference for group homogeneity after controlling for reciprocated similarity • There is peer influence, but not predominantly in groups.

21. some results from Scottish data • Influence question • Are isolates most stable smokers? • No. • neither isolation nor indegree have a significant impact on behavioural preference. • On the contrary… • isolates may be extremely unpredictable (as there is no reciprocation of friendship tempering the influence of their perceived friends).

22. some results from Scottish data • Selection question • Is peripheral smoking rewarded • by acceptance in a smoking group? • Not this easily. • main effect sim×rec on network is negative, so there is a net negative tendency to have additional smokers in a smoking group • question is: does tie creation differ here from tie dissolution?

23. some results from Scottish data • Selection question • Is group smoking punished • by rejection in a non-smoking group? • Not either. • main effect sim×rec on network is negative, so there is a net positive tendency to have smokers in a non-smoking group. • question is again: does tie creation differ here from tie dissolution?

24. some results from Scottish data • Selection question • Does isolate smoking breed further isolation? • ‘Indirect evidence’ supports claim… • smokers are significantly less chosen as friends, • (effect not shown here:) unpopular others are significantly less chosen as friends; isolates are “extreme unpopulars”

25. some results from Scottish data • Literature • E&B S. Ennett & K. Bauman (1993). • Peer Group Structure and Adolescent Cigarette Smoking: A Social Network Analysis. • Journal of Health and Social Behavior 34(3): 226-36. • O&D E. Oetting and J. Donnermeyer (1998). • Primary Socialization Theory: the Etiology of Drug Use and Deviance. • Substance Use and Misuse 33(4): 995-1026. • P&M M. Pearson & L. Michell (2000). • Smoke Rings: Social Network Analysis of Friendship Groups, Smoking, and Drug-Taking. • Drugs: Education, Prevention and Policy 7(1): 21-37. • P&W M. Pearson & P. West (2003). • Drifting Smoke Rings: Social Network Analysis and Markov Processes in a Longitudinal Study of Friendship Groups and Risk-Taking. • Connections 25(2):59-76.