Professor of Psychological Medicine at the University of Edinburgh Professor George Carstairs contemplates the patterns of social anthropology in his Reith series 'This Island Now'. In this lecture entitled 'Vicissitudes of Adolescence', Professor Carstairs explores how violence and sex have been linked to teenage behaviour. Are adolescents more sexually promiscuous? Are teenagers more aggressive? To answer these questions he discusses his own field research in India to compare Hindu communities to British ones, in order to consider how social class affects teenage behaviour.