Laura Kennedy

PhD Title:

Explaining school-based aggression: A situational analysis of peer influence

Abstract: 

Objective: This thesis examines the situational role of aggressive peers in the explanation of school-based aggression. Peer influence research has traditionally been limited by the neglect of person-environment interactions, the failure to specify and test plausible causal mechanisms, and the need for methodological developments. Responding to these challenges, this thesis applies and develops a robust theoretical framework – Situational Action Theory (SAT) – to theorise the mechanisms and conditions of situational peer influence in relation to aggressive behaviour. This thesis also pioneers an innovative application of the Space-Time Budget (STB) method to test this theoretical model and improve the study of aggression and peer influence in schools.

Methods: The multimethod Peer Relations and Social Behaviour (PEERS) Study collected data from a random sample of 396 adolescents aged 13 to 14 at six diverse secondary schools in Cambridgeshire and Peterborough, UK. This study employed a cross-sectional questionnaire followed by STB interviews with a randomly selected subsample of participants (n = 90). The major methodological contribution of the PEERS study was the adaptation of the STB method to collect real-world situational data on the types of peers present in the setting for the first time. This thesis presents situational analyses of this unique STB data alongside traditional additive analyses of survey data to test the situational model of peer influence.

Results: Both situational and individual-level analyses largely supported the situational model of peer influence. Findings showed that (i) aggression was more likely when aggressive peers were present than when adolescents were with non-aggressive peers, (ii) the effect of aggressive peers was greatest amongst adolescents with high aggression-relevant propensity (weak morality and a poor ability to exercise self-control), (iii) weak deterrence was most relevant when adolescents were with aggressive peers, and (iv) the effect of weak deterrence when aggressive peers were present was greatest for high propensity adolescents. Whilst adolescents with high propensity were situationally vulnerable to the influence of aggressive peers and weak deterrence, low propensity adolescents were situationally resistant to these aggression-conducive features of settings.

Conclusion: These findings suggest that adopting a multisystemic approach to the prevention of school-based aggression is essential for maximising the effectiveness of intervention programmes. In addition, targeting aggression-relevant propensity may be more fundamental than reducing exposure to aggression-conducive settings for preventing aggressive behaviour in schools. Finally, the innovative STB method developed in this thesis and the unique real-world situational data collected in the PEERS study can inform future research on peer influence and the situational dynamics of aggressive behaviour in schools.