Background: Adolescence is a period during which humans undergo significant changes in the social cognitive domain – changes that are likely to be adaptive, by allowing adolescents to respond adequately to new challenges as they gain independence from the family, and establish themselves in society. Recent neuroscience data suggest protracted maturation of key brain circuits during adolescence, which are involved in the underlying cognitive processes of social understanding. While these age-associated changes are commonly recognised to arise from a biological program unravelling across time, it is also possible that development is driven by experience. To date, few studies have empirically studied the development of social cognition in adolescence, especially as compared to infancy and childhood. Outstanding questions also remain on whether variability in the experience of adolescence, such as is present across different cultures, can modulate the expression of adolescent-associated maturational changes in social cognition. Aims: The purpose of this thesis was i) to investigate developmental changes in social cognition during adolescence, and ii) to examine sociocultural factors that may influence this ability and its developmental trajectory. Methods: In total, 668 young people (aged 9 to 21 years) from the United Kingdom, China, and Malaysia took part in the studies outlined in this thesis. In Chapter 2 (UK: N = 226; China: N = 175; Malaysia: N = 225), the self-construal scale (Singelis, 1994) was administered to explore the adolescent ‘self’ as an independent entity as well as an interdependent social agent across all cultures. Chapters 3 and 4 consisted of a battery of cognitive and affective theory of mind as well as domain general cognitive tasks, which were completed by adolescents from the UK (N = 188) and China (N = 116). In Chapter 5, a novel social networks paradigm was used with a Game Theory task to investigate the impact of social reciprocity on cooperative investment in authentic adolescent school-based networks from the UK (5 classes; N = 70) and Malaysia (7 classes; N = 147). Results: First, young people from different cultures were characterised by culture-dependent construals of the self. In particular, youths from China defined themselves as more interdependent, i.e. in relation to others and in terms of social roles, than those from the UK and Malaysia. Second, although Chinese adolescents reported overall lower performance, they showed similar age associated changes in cognitive and affective theory of mind as UK adolescents. Finally, social reciprocity predicted cooperative investment behaviour within authentic adolescent networks in both the UK and Malaysia. Interestingly, there were no age effects or differences between cultures in the impact of social reciprocity on cooperative behaviour. Conclusions: Results from this combination of studies paint a multifaceted picture of adolescent social cognition across cultures. They suggest a complex interplay of factors both at the individual and sociocultural level that give rise to the sophisticated ability of social cognition as it matures across adolescence. They also highlight methodological issues in multicultural research
