By B.J. Casey, C. Simmons, L.H. Somerville, and A. Baskin-Sommers

Youthful offenders convicted of serious crimes continue to be sentenced to death and life without parole in the United States based on legal arguments that cast them as incorrigible and permanent dangers to society. Yet psychological and neuroscientific evidence contradicts these arguments and unequivocally demonstrates significant changes in brain, behavior, and personality throughout the life course, especially during adolescence as it extends into the early twenties. This article (a) clarifies the current state of the science on typical behavioral and brain development showing robust changes into the twenties; (b) demonstrates that behavior, personality, and psychopathic traits are dynamic and change over time; and (c) underscores that reliance on prior criminal behavior only to predict later recidivism is tenuous at best. Together, these scientific insights make a case for extending juvenile protections to youthful offenders sentenced for crimes committed in their teens and early twenties. 

Annu. Rev. Criminol. 2022. 5:321–43