The Legal Impact of Adolescent Brain Science: Evidence, Assessments, & PredictionsTerry A. MaroneyVanderbilt University Law School

American Judges Association2013 Annual Education ConferenceBig Island, Hawaii

• Background: The basics of adolescent brain science; tracing its migration out of the laboratory and into legal theory & practice

Evidence & Assessment: What kinds of claims are being made on the basis of adolescent brain science, what is happening to them, and why?

• Predictions: What role is the science likely to play in juvenile justice going forward?

Presentation overview

Basics of Adolescent Brain Science•Main argued differences relative to adult

brains

▫Lesser degree of myelination, esp. in frontal cortex

▫Neural exuberance followed by synaptic pruning

▫Differential recruitment patterns, e.g., greater recruitment of amygdala relative to frontal regions

Myelination

PruningNormal development of the prefrontal cortex from age 5 20. Red indicates more gray matter, blue less. Gray matter wanes in a back to front wave as the brain matures and neural connections are

pruned and higher-order functions developed.

Source: Gogtay, N., et al., Dynamic Mapping of Human Cortical Development during Childhood through Early Adulthood, Proceedings of the National Academy of

Sciences, 101(21):8174-8179, May 25 2004

Differential recruitment• “In a recent study mapping differences between the brains of

adults and teens, Yurgelun-Todd put teenage and adult volunteers through a MRI and monitored how their brains responded to a series of pictures [of fearful faces]. The volunteers were asked to discern the emotion. The results were surprising. All the adults identified the emotion as fear, but many of the teenagers saw something different, such as shock or anger. When she examined their brain scans, Todd found that the teenagers were using a different part of their brain when reading the images.”

• http://www.pbs.org/wgbh/pages/frontline/shows/teenbrain/interviews/todd.html

Teens (left) used less of the prefrontal (upper) region than adults (right) when reading emotion.

Adolescent Brain Science takeaway•Teen brains are structurally and

functionally different from those of both children and adults

•The correspondence between neuroscience and psychology suggests a neural underpinning for teens’ typical behavioral traits

•Normal brain development creates greater capacity for maturity of thought, emotion, and behavior

Adolescent Brain Science: Trajectory from laboratory to law

Graham (2010): “Developments in psychology and brain science continue to show fundamental differences between juvenile and adult minds … parts of the brain involved in behavior control continue to mature through late adolescence.”

Range of post-Roper & Graham legal claims•Sentencing

▫Invalidity of schemes; choice of sentence within range, individual mitigation

•Transfer to adult court▫Invalidity of schemes; individual transfer

decisions•Competence, including ability to waive

rights▫Miranda, consent searches, waiver of

counsel•Mental states

▫Inability to form mens rea; how recklessness and negligence should be construed

Adolescent Brain Science: Trajectory from laboratory to law

Evidence & AssessmentsLegal impact of ABS claims appears minor •When positively cited by courts,

▫one reason among many, ▫usually in support of a general proposition

about youth as a class,▫buttressing behavioral studies & lay

observation•Frequently deemed legally irrelevant,

▫foreclosed by doctrine and/or legislative choices,

▫failing to inform individualized assessment, or

▫duplicative of other evidence as to immaturity

•Sometimes rejected on merits,▫where in conflict with record evidence

Evidence & AssessmentsPositively cited by courts in support of general propositions about youth as a class …• Roper, Graham, JDB, & Miller: “three general

differences”• AL: ABS could be relevant to argument that

“developmental immaturity” should be recognized as a basis for sentencing mitigation under state law

…but does not appear outcome determinative

• NV family court: ABS is one of 5 reasons to invalidate juvenile sex offender registration scheme

• WI Supreme Court, Abrahamson concurrence: ABS is reason 3 of 8 to require parental presence at juvenile interrogations

Frequently deemed legally irrelevant because of …doctrine… •NM: challenge to juvenile’s ability to

premeditate & form specific intent to kill▫Even if true, would amount to “diminished

capacity” defense, not allowed under state law

… and legislative choices• CT: refusal to define “reasonable

person” for duress defense by reference to adolescent traits

▫ Legislature had chosen an “objective” standard

• MN: science does not override legislative transfer scheme

Evidence & Assessments

Frequently deemed legally irrelevant because of …failing to inform individualized assessment•CA (Andy Williams):

▫School shooter had MRI taken of brain pre-plea, had never been analyzed

▫Neither MRI nor expert testimony about ABS likely to generate relevant evidence as to Williams’ mental state

▫Individual examination & diagnosis by psychiatrist both more relevant and sufficient

Evidence & Assessments

Frequently deemed legally irrelevant because of …adding little to other evidence or to “common sense” •Del.: “typical adults can be counted on to

understand that young people make ill-considered and bad judgments,” even if they don’t understand the “physiological underpinnings” for that behavior

•WI: court had considered “youth” as a sentencing mitigator, so did not additionally need to consider evidence of brain development

Evidence & Assessments

Sometimes rejected on merits where in conflict with record evidence•SC (Pittman): ABS cannot show juvenile’s

inability to premeditate, plan, deceive, where independent evidence of those actions

•Del.: ABS expert testified that juveniles’ brain immaturity manifests in poor planning and foresight; neuropsychological tests showed high levels of planning and foresight

Evidence & Assessments

Juvenile justice will continue to be transformed post-Roper & Graham, but not primarily because of adolescent brain science•Maximum weight it can bear: in support

of general propositions about youth as a group▫Pointed, scientific, 21st-century way to

articulate what is different about youth▫Very persuasive at high level of generality▫one reason among many to recommit to a

balanced system of justice for juveniles•Dangers of early overemphasis,

overreliance

Predictions

The False Promise of Adolescent Brain Science in Juvenile Justice, 85 NOTRE DAME L. REV. 89 (2009)

Adolescent Brain Science after Graham v. Florida, 86 NOTRE DAME L. REV. 765(2011)

The Once and Future Juvenile Brain, in CHOOSING THE FUTURE FOR AMERICAN JUVENILE JUSTICE (Franklin E. Zimring & David S. Tanenhaus eds., forthcoming 2014) • In your conference materials

terry.maroney@vanderbilt.eduhttp://ssrn.com/author=447138

For more information