Adolescence, defined as 10-24 years, is a period of life often characterised by behaviours that can appear, prima facie, irrational such as dangerous risk-taking and impulsivity. However, these behaviours can be interpreted as adaptive and rational given that a key developmental goal of this period of life is to mature into an independent adult while navigating a social world that is unstable and changing. Research over the past two decades has demonstrated that social cognitive processes involved in navigating an increasingly complex social world develop, social influence is an important determinant of decision making and areas of the social brain undergo substantial development across adolescence. The findings suggest that adolescence might be a sensitive period of social development.