Over the past decade, important insights have been obtained into the neurocognitive development during adolescence. To better understand how these neuroscientific insights impact the real world, we investigated how neuroscience has shaped public perceptions of the “teenage brain” and if these perceptions influence adolescent behavior. When asking to generate free associations with the word “teenage brain,” adolescents ( n = 363, M age = 14.47 years) and parents ( n = 164, M age = 47.16 years) more often mention undesirable behaviors (e.g., “irresponsible”) than desirable behaviors (e.g., “creative”). Despite these dominantly negative associations, priming adolescents with positively versus negatively framed statements about adolescent brain development did not influence their subsequent risk-taking, impulsivity, and performance on response-to-failure tasks. However, we did find a more nuanced effect, related to how much adolescents agreed with the negative versus positive priming statements: Adolescents' negative beliefs about adolescent brain development reinforced negative behaviors by increased risk-taking behaviors, and adolescents' positive beliefs reinforced positive behaviors by using positive strategies to cope with academic setbacks. The current findings underline the impact of views that build up over time and that these are not easily influenced by a one-time instance of information but rather reinforce the impact of new information. To prevent negative perceptions of the teenage brain from becoming self-fulfilling prophecies, it is important that communication about adolescent neurocognitive development is framed in a more balanced way. Neuroscientists need to be more aware of how their research impacts the real world, before we are fully ready for “real-world neuroscience.”