Post on 25-Feb-2016
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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
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