The false promise of adolescent brain science in juvenile justice.

• Author: Maroney, Terry A.

Recent scientific findings about the developing teen brain have both captured public attention and begun to percolate through legal theory and practice. Indeed, many believe that developmental neuroscience contributed to the U.S. Supreme Court's elimination of the juvenile death penalty in Roper v. Simmons. Post-Roper, scholars assert that the developmentally normal attributes of the teen brain counsel differential treatment of young offenders, and advocates increasingly make such arguments before the courts. The success of any theory, though, depends in large part on implementation, and challenges that emerge through implementation illuminate problematic aspects of the theory. This Article tests the legal impact of developmental neuroscience by analyzing cases in which juvenile defendants have attempted to put it into practice. It reveals that most such efforts fail. Doctrinal factors hamstring most claims--for example, that persons with immature brains are incapable of forming the requisite mens rea for serious crimes. Limitations intrinsic to the science itself--for example, individual variation--also hinder its relevance and impact. These factors both explain why developmental neuroscience has had minimal effects on juvenile justice in the courts and illustrate why it generally should. Moreover, direct reliance on neuroscience as the metric for juvenile justice policy may jeopardize equality and autonomy interests, and brain-based arguments too frequently risk inaccuracy and overstatement. The cases also strongly suggest that neuroscience does not materially shape legal decisionmakers' beliefs and values about youthful offenders but instead will be read through the lens of those beliefs and values.

Developmental neuroscience nonetheless can play a small role in juvenile justice going forward. Legislatures and courts may regard that science as one source among many upon which to draw when basing policy choices on assumptions about juveniles as a group. To go further is unwarranted and threatens to draw attention away from critical legal and environmental factors--good schools, strong families, economic opportunities, mental health care, humane sentencing regimes, and rehabilitative services--that are both more important and subject to greater direct control.

INTRODUCTION I. ADOLESCENT BRAIN SCIENCE AND JUVENILE JUSTICE: AN OVERVIEW A. Developmental Psychology and Neuroscience B. The Brain-Based Challenge to the Juvenile Death Penalty C. Adolescent Brain Science Beyond Roper II. THE LIMITED IMPACT OF ADOLESCENT BRAIN SCIENCE IN THE COURTS A. Doctrinal Obstacles 1. Adult Punishment 2. Transfer to Adult Court 3. Mental States B. Scientific Limitations 1. Individual Differences 2. Structure v. Behavior 3. Relative Deficiency 4. Age Limits 5. Equality and Autonomy Commitments C. Advocacy Pressures III. A LIMITED ROLE FOR ADOLESCENT BRAIN SCIENCE WITHIN JUVENILE JUSTICE CONCLUSION INTRODUCTION

This is the decade of the adolescent brain. Popular media sources claim that contemporary developmental neuroscience (1) shows "What Makes Teens Tick" and explains their "exasperating" behavior, including criminal acts. (2) Allstate Insurance released a major national ad claiming that teens are "missing a part of their brain [s]" and therefore should gain driving privileges only gradually. (3) Parents can now choose among a number of self-help books offering brain-based explanations for why their adolescents are "primal" and "crazy." (4)

Far from being confined to popular culture, the fascination with adolescent brain science has begun actively to percolate through legal theory, advocacy, and lawmaking. Prominent academics argue that an understanding of the teen brain both supports retention of a separate juvenile justice system and illuminates the proper perspective on the adjudication and treatment of young offenders. (5) Crimes committed by still-developing young people, these scholars urge, are less blameworthy than equivalent acts by adults; further, youths' developmental plasticity makes them more likely to stop offending--if, that is, we provide them with conditions conducive to rehabilitation. (6) Juveniles' defense attorneys and policy advocates increasingly cite to such research, which they say puts "the juvenile back in juvenile justice." (7) Prosecutors, too, recognize the potential relevance of neuroscience, though they are less sanguine about whether its necessary policy implications tend in the direction of greater solicitude. (8) More, courts and legislatures have begun to take note. United States Supreme Court Justice Stevens in 2002 signaled his interest in "[n]euroscientific evidence" which "has revealed that adolescent brains are not fully developed." (9) Senator Edward Kennedy in 2007 convened a hearing on the juvenile-justice implications of brain development. (10) Many scholars, attorneys, commentators, and courts believe that such science played a critical role in Roper v. Simmons, (11) in which the Supreme Court abolished the juvenile death penalty. (12) Many now assert that brain science might, and should, play an even larger role going forward.

This Article argues that, contrary to the high expectations many have placed on developmental neuroscience, it will--and should--have fairly modest effects on juvenile justice. Not only is this correct as a matter of theory, it is being borne out in practice. To show how this is so, this Article offers the first attempt systematically to identify and analyze cases in which advocates have attempted to put developmental neuroscience into practice. The case analysis demonstrates that most such efforts fail, for two primary reasons: a disconnect between scientific findings and the questions asked by legal doctrine, and limitations posed by the science itself. Though the analysis reveals instances in which courts cite approvingly to brain-science arguments, in no such case does that science appear to have been outcome-determinative.

The relative inefficacy of brain science in influencing court outcomes illuminates significant theoretical and practical barriers to such influence. Those barriers counsel that that the trend toward urging reliance on such science be significantly moderated.

The Article proceeds as follows. Part I explains the ascendance of the teen brain within juvenile justice as a product of three streams' confluence: juvenile justice's close historical relationship with developmental psychology, a science that began a significant expansion in the 1980s; the radical growth of neuroscience, including developmental neuroscience, in the 1990s; and an emerging post-2000 dialogue between legal scholars and neuroscientists. Importantly, this confluence coincided with a widespread, sharp move away from traditional juvenile justice values, (13) as virtually every state in the 1990s began to treat far more juveniles as adults and to shrink the benefits--such as confidentiality--youth previously had enjoyed. Scholars and advocates began to see brain research as a tool to close an apparent disjuncture between science, which increasingly showed that juveniles and adults are different, and law, which increasingly treated juveniles and adults as if they were the same. Efforts to abolish the juvenile death penalty reflected this new tactic. That the Supreme Court appeared to take cognizance of the science--and did, in fact, eliminate the death penalty--provided significant encouragement to that project.

Part II demonstrates that, despite projections, adolescent brain science has had, is likely to have, and should have only moderate impact in the courts. First, courts tend to regard even scientifically sound claims as legally irrelevant. For example, contemporary analysis of intentional mens rea asks only whether a defendant desired or knew that a result would obtain, while neuroscientific arguments invite a focus on substantive irrationality notwithstanding specific intent. Second, scientific limitations often hinder such claims. For example, because developmental neuroscience supports only probabilistic generalizations about youth as a class, it is unhelpful in making highly individualized determinations such as formation of intent. Direct reliance on neuroscience also has implications for equality and autonomy commitments, of which scholars and advocates have taken insufficient notice. Further, the pressures of advocacy incentivize defenders and advocates to downplay the legal-scientific mismatch or to overplay scientific findings (and incentivizes prosecutors and skeptics to do the opposite). Such distortions, not unique to the juvenile justice context but present in it, create a danger of poorly justified decisions.

Part III, however, argues that neuroscience nonetheless has a role--albeit a small one--to play in shaping juvenile justice policy. Neuroscience has more natural traction within juvenile justice than in adult criminal law. Rather than raising deep and likely unsolvable questions about human agency, it simply reinforces the (once) non-controversial idea that, as a group, young people differ from adults in systematic ways directly relevant to their relative culpability, deterrability, and potential for rehabilitation. This message is well worth articulating; the cautionary point is that the theoretical and advocacy uses of adolescent brain science should mirror only the level of generality that the science can support. At this moment, that level of generality is fairly high. Similar lessons from the broader contemporary debate over the use of neuroscience in criminal law have not yet penetrated the dialogue within juvenile justice; this Article shows that they should. More, while neuroscientific evidence may be thought uniquely persuasive, this Article instead suggests that developmental neuroscience is legally persuasive only insofar as it aligns with decisionmakers' values, beliefs, and commitments.

The Article concludes that...