A PMHNP evaluating a 16-year-old male for impulsive behavior and risk-taking considers whether his presentation reflects psychopathology or normal neurodevelopmental processes. The adolescent's parents report that he makes reckless decisions with peers despite being able to reason well in calm one-on-one conversations. His neuropsychological testing shows intact cognitive function. The PMHNP reviews the neurodevelopmental basis of adolescent decision-making. Which of the following best explains the neurobiological basis of adolescent risk-taking behavior?