Criminal responsibility of adolescents
Because children are typically considered insufficiently responsible, their cases are not heard in adult court, while adults are legally presumed fully responsible. Adolescents lie somewhere in the middle of this continuum.
A successful insanity defense negates criminal responsibility. Adolescents rarely use an insanity defense, in part because the incidence of psychosis is considerably lower in adolescents than in adults, and in part because youths who are so obviously mentally ill as to qualify for an insanity defense are often not waived to adult court. While it is fairly clear that adolescents overall are less blameworthy than adults, it is often unclear in a particular case how much less blameworthy a particular adolescent is. Psychiatrists may be called on to consult in such cases to assist in determining the adolescent's culpability.
Developmental considerationsof adolescent aggression and impulsivity
One metaphor sometimes used in discussing adolescent aggression is that compared with adults, adolescents have their foot on the gas and have inadequate brakes. The literature reveals a number of key findings about adolescent development that are important to keep in mind when evaluating juvenile offenders for the courts.
For most youths, the onset of serious violence is an adolescent phenomenon, with a peak age of onset at around 16.5 If a person has not acted violently before age 21, the likelihood he or she will ever do so is quite low.
Serious violent offending (defined as aggravated assault, robbery, gang fights, or rape) is surprisingly common in adolescence: the Surgeon General's report on youth violence noted that 30% to 40% of boys and 16% to 32% of girls had committed a serious violent offense by age 17.6
For most youths, offending is limited to adolescence. About 80% of adolescent violent offenders stop offending when they reach adulthood, and fewer than half of those who do continue have an adult career of violence that lasts longer than 2 years.6
There is little evidence to suggest that one can accurately predict who will go on to offend as an adult and who will not. Some data suggest that delinquents who continue their criminal behavior into adulthood have different developmental patterns: those who persist in criminal activity tend to have a worsening of impulsiveness and ability to suppress their aggression, rather than the improvement that typically comes with maturation.7
Serious violence is typically the end of a developmental progression of offenses that begins with low-level offenses (vandalism and shoplifting), progresses to nonconfron-tational offenses (theft), and then to violent offenses (aggravated assault and rape).5 Delinquents do not begin their antisocial activities by shooting someone.
Finally, adolescent crime is different from adult crime. Adolescents typically offend in groups, while adults typically offend alone. Also, adolescent crime tends to be more impulsive than adult crime.8Adolescent culpability is a complex concept. A number of factors should be assessed in evaluating the criminal responsibility of an adolescent offender (Table 2).9
The area that has received the most attention is adolescent immaturity and impulsivity. Cauffman and Steinberg10 found that lower levels of psychosocial maturity correlated with more decisions to commit antisocial acts. Moreover, psychosocial maturity was a more significant predictor than age. Considerable research has further refined our views of components of adolescent judgment; such factors as risk-taking, reward-seeking, impulsivity, and self-regulation have been used to argue for mitigation of adolescent culpability.11,12
Over the past decade, there has also been considerable research on adolescent brain development. The findings are consistent with a biological explanation for the behavioral findings in adolescence and point to an evolving understanding of why adolescents overvalue immediate rewards and lack the impulse control of mature adults.13-15 These findings show that the limbic system, responsible for emotions, matures before the prefrontal cortex, which is responsible for executive functioning. Furthermore, the tracts between the prefrontal cortex and the limbic system continue to be myelinated through adolescence.