In recent years, criminal law has been adapting to scientific findings about adolescent behavior. So far, most of these adaptations have applied only to cases involving violent crime committed by youth or in which a juvenile would face the death penalty or life imprisonment. Because changes in the law’s approach to juveniles appears to be limited to severe cases, we’re left questioning what the scope of this change ought to be. Supreme Court precedent and recent scholarship suggest that, if our legal system is to be fair, it will have to continue to adapt to reflect the reality of the differences between adolescents and adults.
In Roper v. Simmons, the Supreme Court held, based in part on the unique characteristics of the developing adolescent brain, that sentencing a minor to death is “cruel and unusual punishment” prohibited by the Eighth Amendment. More recently, in Graham v. Florida, the Court also held that it is unconstitutional to sentence juveniles to life imprisonment for non-homicide crimes. Both cases relied heavily on recent scientific studies, which found that adolescents are simply wired differently from adults. They lack the brain development to be truly “morally culpable,” but have a greater capacity for rehabilitation. Because of those studies, sentences that were previously considered to be fair, are now unconstitutional.
There is mounting evidence that the actual, biological, age of maturity doesn’t occur until a person’s early 20s. The parts of the brain that are involved in culpability, “those relevant parts that govern impulsivity, judgment, planning for the future, foresight of consequences” are not fully mature until after the legal age of adulthood, which can be anywhere between 14 and 18. This conclusion has been compelling courts and legislatures throughout the country to change how we sentence young defendants.
Each year, there are more studies that support the conclusion that the growing mind has a limited facility to make sound moral judgments and calculate risk. Just last month, a new study out of Oxford University concluded that teens’ ability to asses risk is compromised. The study, by Jennifer Lau, Ph.D., found that teens rely more on the hippocampus and right amygdala to asses threats, while adults rely more on the dorsolateral prefrontal cortex (DLPFC). The hippocampus and amygdala are “older” parts of our brain, associated with storing memories and the “fight or flight” response. The DLPFC, in contrast, develops later and is involved in higher-level distinguishing. Teens’ compromised facility to asses risk suggests that when it comes to responsibility and culpability, it might be unreasonable to expect teens to act with the same foresight we expect adults to use.
The argument that brain development should be linked with culpability and sentencing is not always successful. The Supreme Court of Wisconsin, in Ninham v. State, just ruled that the state can sentence children as young as 14 to life imprisonment without the possibility of parole for intentional homicide. The defendant in that case argued that new scientific research on adolescent brain development was a “new factor” that should be considered by the court. But the court rejected that argument. Instead it found that the new studies of MRI simply supported the proposition that adolescents are less culpable than adults—a widely agreed upon theory that the court agreed was in existence before Ninham was sentenced.
The dissenting judges, however, did find the arguments of the Wisconsin Psychiatric and the Wisconsin Psychological Associations compelling. And they noted that similar scientific evidence has guided the decisions of the Supreme Court of the United States and the courts of several other states. The US Supreme Court has yet to weigh in on this issue, but considering the Roper and Graham decisions, they may side with the Wisconsin court’s dissent and new scientific studies.
What does this all mean for the future of criminal law? Our justice system and ideas of fairness are founded on reason. As our knowledge about the world evolves, our justice system evolves with it. Back in the middle ages, people thought of children as petite adults. But advances in philosophy, technology, and science changed our view about the nature of children; and we changed their culpability along with it. Now we have more scientific evidence demonstrating that children aren’t yet mentally equipped to be reasonably relied on to behave as we expect adults to. We’re operating with different hardware. Considering the science and history of legal evolution, it’s only a matter of time before our laws reflect the realities of scientific findings.