The line between adolescence and adulthood varies greatly in U.S. legal and social policy, with little consistency in determinations about the age at which one may purchase alcohol or cigarettes, drive, make medical decisions, join the military, vote, or be tried for a crime as an adult. Although there is strong consensus among neuroscientists that there are significant changes in brain structure and function during adolescence, there has been no clear mechanism whereby this knowledge can be used to inform legal and social policy decisions. Steinberg (2009) outlined four important structural changes in the adolescent brain that may have policy implications: (1) a decrease in gray matter, likely due to synaptic pruning, is accompanied by improvements in logical reasoning and information processing, (2) a reorganization of dopamine receptors increases dopaminergic activity in the prefrontal cortex, which may cause greater receptivity to rewarding stimuli – and possibly greater sensation seeking, (3) an increase in myelination of the prefrontal areas is associated with improvements in executive function, such as planning or weighing consequences of actions, and (4) an increase in connections among cortical areas as well as between cortical and subcortical areas is associated with improved processing of emotional and social information. Steinberg noted that it is impossible to identify the point at which an adolescent becomes capable of adult brain functions, though it seems clear that teenagers are less neurobiologically mature than once thought. This may call for policies that take neurobiological maturity levels into account by offering greater protections as well as restrictions. Steinberg warned that while neuroscience is useful in developing legal and social policies, it is less useful in determining the outcomes of individual cases, since it is not currently possible to assess an individual’s level of neurobiological maturity. Further, because the public tends to view social science research as more credible when there is a neuroscience component, such information should be presented with caution.
Should the Science of Adolescent Brain Development Inform Public Policy?
Steinberg, L. (2009). Should the science of adolescent brain development inform public policy? American Psychologist, 64, 739-750.
Adolescence Brain Neuroscience Risk takingMedia Supplement
View chapters from the PBS Frontline film Inside the Teenage Brain and find links to resources on this topic.