The brain continues to develop significantly during adolescence. Following a period where brain cells proliferate in the frontal region leading up to puberty, this area undergoes maturation that extends into early adulthood. Because the frontal lobes—responsible for judgment, impulse control, and planning—are not yet fully developed, adolescents may exhibit increased risk-taking behaviors and emotional outbursts. This ongoing development also explains why, as neuroscientist Jay Giedd notes, it is unreasonable to expect teens to possess adult-level organizational or decision-making skills before their brains are fully constructed.