This briefing paper is part of a mini-series on ‘The Brain Under Construction’. This paper looks at the structure and function of the brain and considers the uniqueness of the adolescent brain. Pictures of the brain in action show that adolescent’s brains work differently than adults and scientific research is showing that the brain systems involved in decision-making, planning, social understanding and risk-taking are developing in adolescence. This research could have implications for education, rehabilitation and intervention.