The adolescent brain has become a flourishing project for cognitive neuroscience. In the mid 1990s, MRI studies mapped out extended neuro-development in several cortical regions beyond childhood, and during adolescence. In the last ten years, numerous functional MRI studies have suggested that functions associated with these brain regions, such as cognitive control and social cognition undergo a period of development. These changes have been anecdotally and clinically used to account for behavioural changes during adolescence. The interpretation of these data that the "teen brain" is different has gained increasing visibility outside the neuroscience community, among policy makers and in the media, resonating strongly with current cultural conceptions of teenagers in Western societies. In the last two years, a new impetus has been placed on public engagement activities in science and in the popular science genre of the media that specifically attempts to educate children and teenagers about emerging models of the developing brain. In this article, we draw on data from an adolescent focus group and a questionnaire completed by 85 teenage students at a UK school, to show how teens may hold ambivalent and sometimes resistant views of cognitive neuroscience's teen brain model in terms of their own self-understandings. Our findings indicate that new "neuro"-identity formations are more fractured, resisted and incomplete than some of the current social science literature on neuro-subjectivities seem to suggest and that the effects of public policy and popular education initiatives in this domain will be more uneven and complex than currently imagined.