Background: As a developmental period, adolescence is critical for the formation of health behaviours that are carried into adulthood. The social reorientation that occurs during adolescence marks an important stage in development when normative influences become more salient, and social pressures to conform to the behaviours of peers increase in their magnitude and regularity. One behavioural outcome that is examined consistently in the literature is smoking, the social antecedents of which are well-documented and have been explored using a range of different theoretical models which are explored in Chapter 2.

While social norms are important determinants of smoking behaviour, they are not universal across all contexts. For example, in low-middle-income countries tobacco advertising is more prominent and smoke-free regulatory frameworks are not consistently implemented. As a result, the global burden of tobacco-related disease has shifted to low-middle-income settings where the tobacco industry can circumvent local tobacco legislation with relatively little resistance. By comparison, smoking rates in high-income countries are significantly lower and Chapter 3 investigated how the factors that contribute to smoking differ across these contexts.

Despite a large body of research delineating the normative and psychosocial antecedents of adolescent behaviour, there are few studies that have attempted to expound upon the specific personality and cognitive traits that make adolescents more susceptible to normative influence. Therefore, the objective of Chapter 4 was to explore the psychosocial and cognitive traits associated with sensitivity to social norms using a novel experimental tool designed to gauge adolescent’s norms sensitivity using a modified version of a rule-following task.