Brain Science and the Theory of Juvenile Mens Rea

In recent decisions the Supreme Court has forged new Eighth and Fourth Amendment jurisprudence by relying on an emerging body of scientific data focused on adolescent thought processes and decision making. This data prompted the Court both to restrict the application of certain punishments for youthful offenders and to require an adolescent-calibrated assessment of custody for Miranda purposes. The logic of these recent decisions and the science upon which they are based counsels toward a similar adolescent-calibrated assessment of mens rea in criminal law.

The Court and the Science

In Roper v. Simmons the Supreme Court held that the Eighth Amendment prohibited imposing the death penalty on juvenile offenders. In its decision the Court recognized what most parents of teenagers have long suspected: kids are different than adults. More specifically teenagers think differently than their adult counterparts. This is hardly a novel revelation – the law and adults everywhere had long drawn distinctions between juveniles and adults. There are age-based restrictions on when you can drink, vote, drive a car, or even get a tattoo. These restrictions are justified by an abiding belief that people younger than the designated age boundary are too immature to responsibly make the decision required for each of the activities. That these categories are broad and often imprecise (just ask any 45 year-old what they think of the tweety bird tramp stamp they legally obtained at 17) does not undermine the validity of the premise on which they are based: The average teenager is more likely to engage in poor judgment than the average adult, often with dire consequences if not for the state’s benevolent, if not paternalistic, guiding hand. What made Roper different than past age restriction cases was not only that it barred imposition of the ultimate penalty (the death penalty) on youthful offenders but that it relied in no small part on emerging scientific data to support its decision.

In the cases that followed Roper – Grahamand Miller – the Court expanded its analysis to encompass sentences of life without the possibility of parole and, in some cases, life with the possibility of parole for youthful offenders. In these cases, the Court echoed the logic and scientific basis identified in Roper – kids were different and so the Eighth Amendment protected them in different ways than their adult counterparts. Most recently in J.D.B. v. North Carolina the Court extended this reasoning to Miranda’s custody analysis as applied to juveniles – requiring courts to apply a “reasonable juvenile” standard to determine whether or not a child reasonably believed he was in custody.

The logic of these decisions is hardly a leap. That juveniles think differently seems to be an inherently known and accepted fact. That we, as adults, understand that their thinking is differently in turns counsels that we should treat them differently – which we in fact do. But it also means that when we think in terms of their culpability or their understanding of the world around them we have to think differently as well. As neuroscience’s ability to delve into the biological mechanics of thought processes advances, it provides us with the scientific justification for what we also seem to inherently understand. The difference is, it also suggests that whatever differences we have recognized and embraced so far, we have not done enough. We still cling to an adult referential state of mind analysis when we decide whether or not the juvenile was guilty in the first place. Such an adherence to a one size fits all state of mind analysis not only defies what we all seem to inherently know about adolescents in our midst, but defies the scientific evidence the Court has been so keen to rely on as of late in constructing the modern jurisprudence of youth.

So what does the science say? Review of the literature reveals several relevant findings. Compared to adults, adolescents demonstrate deficiencies in their capacity for autonomous choice, self-management, risk perception, and the calculation of future consequences. They are more likely to take risks and to be sensation-seeking. They are more vulnerable to peer influence and display heightened responses to rewards. Their personalities and character are in flux. Even in mid-adolescence as teens’ cognitive capacities approach those of adults, they are less-skilled than their adult counterparts in using these capacities to make real-life decisions. These “deficiencies” in comparison to adults are not defects, but the products of normal physiological and psychological development during the adolescent period. As one researcher concluded, the teen brain is not defective, but “sculpted by both biological and experiential factors to adapt to the unique social, physical, sexual, and intellectual challenges of adolescence.” While the timing and the trajectory of development vary among individuals, the characteristics consistently manifest across the class. Individual variance notwithstanding, these characteristics are distinct and unique to this period of development, contributing to immature judgment and an increased process of exploration and experimentation that may include criminal activity. In short, if adolescence is characterized as a period of rapid change and development, what distinguishes it most obviously from childhood or adulthood is that it is also a time of boundary-pushing and reckless behavior.

The Science and Mens Rea

Given these findings, it hardly seems a leap to conclude that juveniles shouldn’t receive the highest available sentence or even the second highest automatically or that they might see themselves in custody in instances where an adult might not reach the same conclusion. But it is equally apparent, to me at least, that attempting to interpret a teenager’s actions or decisions through the lens of an adult’s thought process seems equally illogical. This lands me squarely at odds with the current application of mens rea to juvenile offenders.

To explain this position, it helps to think first in terms of what we actually hope to accomplish in ascertaining the offender’s state of mind. I learned as a public defender, and teach as a professor, that mens rea serves a unique role in substantive criminal law. An act or a harm may trigger our attention, and our State imposed censure, but it is the actor’s state of mind that informs our assessment of the true level of culpability. An accidental act does not incur State punishment in the same way that a calculated or intentional act does. It is the difference Holmes’ dog helpfully acknowledged between the intentional kick and the stumble. One is punished lightly, maybe even not at all, the other unleashes the full fury of the criminal law.

But in discerning the difference between the stumble and the kick lies the rub. In the end, whether by a defendant’s confession or the analysis of circumstantial evidence, the fact finder is left to unravel what exactly the defendant was thinking. In this, the fact finder lines the defendant’s actions and any explanation he may have offered for those actions against what the fact finder knows of his own world, and decides: did the defendant act intentionally, knowingly, recklessly or negligently? Did the defendant reasonably defend himself or others or property? Did the defendant suffer from some misperception of facts that might mitigate his culpability? Is the defendant so mentally deficient or damaged as to exclude him from culpability altogether or at least exclude him from criminal sanction? To reach this answer, the defendant’s actions and words are filtered through the fact finder’s own thought processes. Whatever we might say about this analysis, as a practical matter it means that all mens rea determinations bear the mental imprint of the fact finder(s) who made those determinations. And most of the time, this may be ok. The fact finder is able to reasonably ascertain what a defendant was thinking based on what the fact finder believes he would have been thinking in the same circumstances. A fact finder can conclude that the defendant meant to kill his cheating spouse because the fact finder can imagine if he learned that his wife was cheating on him and went home and got his gun and drove to the hotel room where his wife lay with her lover and kicked open the door and shot her that he, the fact finder, would have planned to and meant to kill her.

But all this assumes that the fact finder can think like or reasonably like the defendant and in the process can properly assign a mental state to evidence of the defendant’s actions or words. Any single act – driving to the hotel, brining the gun, firing the gun – show premeditation and intent when performed by people who share a thought process and impulse control mechanism that are reasonably the same. But if the thought process is different, or the understanding of the risk associated with the acts, changes, so too must the calculation of state of mind. Brain science tells us that adolescents think differently than those of us who have survived to adulthood. They act more impulsively, they don’t see or appreciate apparent risks in the same way adults do, they are more likely to thrill seek. It’s not just that kids are different than adults, it is that their whole mental processes function differently than adults. And so, in judging their mental state, fact finders must not only know what a defendant did or said, but how his mind would have processed the decision to do or say those things in the first place. And just like a one size fits all adult standard will not do for all fourteen year olds longing to drive cars, or vote, or drink, or tattoo their lower backs, it will not do to determine the mens rea of those same fourteen year-olds accused of a crime.

This is an adaptation of an article that is forthcoming in the North Carolina Law Review. The complete article can be found here.