Funded from 1995 to 2017.
About This Network
When the MacArthur Foundation’s Network on Adolescent Development and Juvenile Justice began its work in 1997, the juvenile justice system had grown increasingly punitive and the boundaries between the juvenile and criminal systems had eroded.
Alarmed by a rising tide of crime, states across the country had increased the transfer of teenage offenders to adult courts and the use of harsher sentences for those convicted of crimes.
This trend disregarded an essential principle underlying the existence of a separate juvenile justice system: that children are less mature than adults, and that the legal system that deals with them should reflect that reality.
The ADJJ network set out to explore that premise, drawing from and expanding upon the latest research on child and adolescent development.
Its members, with expertise in social science, neuroscience, and legal policy and practice, launched three major research studies and several smaller research projects. Their publications, including eight books and monographs and 212 articles in peer reviewed journals and books, have had a notable influence on how juveniles are treated within the American justice system.
The network’s research agenda that revolved around three key themes:
Network members wanted to know if teenagers are less able than adults to understand the trial process and participate meaningfully in their defense.
They launched the first large-scale study to examine these questions and discovered that there are, indeed, significant differences in adjudicative competence between adolescents and adults.
Before the age of 16, researchers learned, young people are significantly less likely to appreciate the nature and importance of legal proceedings, provide relevant information to lawyers, and make well-reasoned judgments about their individual circumstances.
Network participants also wanted to know if teenagers who engage in illegal activities are less mature than adults in ways that render them less blameworthy under the law. Should the justice system take developmental considerations into account when responding to juvenile crime?
Another research study sponsored by the network demonstrated that although teens appear to become intellectually mature by the age of 16, they remain socially and emotionally immature much longer.
This residual immaturity is expressed by poor impulse control, lack of foresight, inadequate assessment of risk, and vulnerability to peer pressure – issues that should be taken into consideration when considering juvenile’s culpability, the network concluded.
It would be advantageous to discover how often juvenile offenders grow out of antisocial behaviors and under what conditions, network members reasoned. Could risk factors for continued criminality and the odds of responding well to various interventions be identified?
The most intensive study of serious juvenile offenders ever undertaken yielded a mixed answer. On the one hand, the study showed that 90 percent of juvenile offenders -- even those convicted of very serious crimes – turn away from antisocial behavior as they age. However, predicting which adolescents were most likely to persist in delinquency and which treatments were most likely to be successful proved extremely difficult.
The implications of the network’s work have been substantial. Notably, the Supreme Court drew upon research on adolescent development and legal culpability in 2005 in a landmark decision, Roper v. Simmons, which outlawed the death penalty for teenagers under the age of 18.
Five years later, and drawing on the same logic, the Supreme Court ruled that teenagers who had committed crimes that did not result in someone’s death could not be sentenced to life in prison without the potential for parole, in Graham v. Florida.
Several states have raised the age at which adolescents can remain under the jurisdiction of the juvenile justice system. Others now require that a young person’s legal competency be assessed before he or she is transferred adult court.
The network also made a significant contribution to that practice by developing tools and materials that help lawyers and judges appreciate developmental issues and assess young people’s legal competency.
Trajectories of Desistance And Continuity In Antisocial Behavior Following Court Adjudication Among Serious Adolescent Offenders
Researchers: Edward P. Mulvey, Laurence Steinberg, Alex R. Piquero, et al.
This seven year study looked at 1,355 juvenile offenders (ages 14 to 17) convicted of felonies or serious misdemeanors in Phoenix and Philadelphia. It discovered that fewer than 10 percent continued to commit crimes as they moved into young adulthood. Ongoing criminality was more likely among juvenile offenders with substance abuse problems, poor impulse control, multiple prior offenses, and a family history of crime. But these factors weren’t sufficient to predict which young people would turn away from antisocial behavior and which would continue to engage in wrongdoing.
Are Adolescents Less Mature Than Adults?
Researchers: Laurence Steinberg, Elizabeth Cauffman, Jennifer Woolard, et al.
This study looked at how young peoples’ cognitive and psychosocial capacities change over time. Interviews and tests were administered to 935 individuals (ages 10 to 30) in Los Angeles, Denver, Philadelphia, Washington D.C., and Irvine, California. Researchers found that adolescents become mature cognitively by the age of 16. But psychosocial maturity is delayed for several years beyond that point, affecting adolescents’ impulsivity, susceptibility to peer pressure, sensation seeking and ability to assess risk at least until the age of 18 and in some cases for years thereafter.
Juveniles’ Competence to Stand Trial: A Comparison of Adolescents’ and Adults’ Capacities as Trial Defendants
Researchers: Thomas Grisso, Laurence Steinberg, Jennifer Woolard, et. al
This large study examined how age affects a person’s ability to participate meaningfully in criminal proceedings. Interviews were conducted with 1,400 youth and young adults (ages 11 to 24) in Philadelphia, Los Angeles, northern Florida, and Virginia. Researchers found that adolescents 15 years old and younger were significantly less able to understand the trial process and appreciate the long-term consequences of their decisions. Also, teens 15 years and younger were more likely to confess to crimes and accept plea agreements without fully grasping the potential risks associated with these actions.