Adolescent Brain Development - the Youth Advocacy Division

• “Although states may hold youths accountable for the harms they cause, Roper explicitly limited
the severity of the sentence a state could impose on them because of their diminished
responsibility. Even after youths develop the nominal ability to distinguish right from wrong,
their bad decisions lack the same degree of moral blameworthiness as those of adults and warrant
less severe punishment.” (3)
• “The court [in Roper] recognized that youths are more impulsive, seek exciting and dangerous
experiences, and prefer immediate rewards to delayed gratification. They misperceive and
miscalculate risks and discount the likelihood of bad consequences. They succumb to negative
peer and adverse environmental influences. All of these normal characteristics increase their
likelihood of causing devastating injuries to themselves and to others. Although they are just as
capable as adults of causing great harm, their immature judgment and lack of self-control reduces
their culpability and warrants less-severe punishment.” (6)
• “Roper’s diminished responsibility rationale provides a broader foundation to formally recognize
youthfulness as a categorical mitigating factor in sentencing. Because adolescents lack the
judgment, appreciation of consequences, and self-control of adults, they deserve shorter sentences
when they cause the same harms. Adolescents’ personalities are in transition, and it is unjust and
irrational to continue harshly punishing a fifty- or sixty-year-old person for the crime that an
irresponsible child committed several decades earlier.” (10)
Hillary Massey, 8 th Amendment and Juvenile Life Without Parole after Roper, 47 B. C. L. REV. 1083
(2006).
• Argues for elimination or limitation of JLWOP based on proportionality review and diminished
culpability of juveniles.
• “The psychosocial research shows strong differences between adolescents and adults that
implicate assessments of culpability. Researchers have identified four psychosocial factors that
affect the way adolescents make decisions, including whether to commit a crime or an antisocial
act: peer influence, attitude toward risk, future orientation, and capacity for self-management. In
one study, adolescents on average scored significantly lower than adults on these factors and
displayed less sophistication in decision making. Although individual levels of these factors are
more predictive of antisocial decision making than chronological age alone, researchers found
that the period between ages sixteen and nineteen is an important transition point in psychosocial
development.” (1090)
Staci Gruber & Deborah Yurgelun-Todd, Neurobiology and the Law: A Role in Juvenile Justice? 3 OHIO
ST. J. OF CRIM. L. 321 (2006).
• Summarizes adolescent neurobiology research and argues that brain differences due to immature
development, like brain differences due to disease, be taken into account in justice system.
• “[N]eurobiological studies … indicate that the cerebral cortex undergoes a dynamic course of
metabolic maturation that persists at least until the age of eighteen. … Younger, less cortically
mature adolescents may be more at risk for engaging in impulsive behavior than their older peers
for two reasons. First, their developing brains are more susceptible to the neurological effects of
external influences such as peer pressure. Second, they may make poor decisions because they are
cognitively less able to select behavioral strategies associated with self-regulation, judgment, and
planning that would reduce the effects of environmental risk factors for engaging in such
behaviors.” (330)
• Steps for defense attorneys to take to understand a client’s state of mind and baseline levels of
functioning are listed on p. 332.