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  • Writer's pictureCaitlyn Greene

Juvenile brains are different, their mens rea analysis should be too

Updated: Oct 16, 2023

Courts should apply a child-centered mens rea analysis for all cases adjudicating juveniles, also known as the “reasonable child” standard. Mens rea is critical in criminal law because levels of culpability are delineated based on varying levels of intent. Whether the statute calls for an objective or subjective state of mind, the fact-finder must determine the juvenile's state of mind. The objective standard of intent is frequently called a “reasonable person” standard, and with an underlying understanding of neuroscience, a child-centered mens rea analysis is necessary because it is consistent with the role of mens rea in assessing culpability. In juvenile court, or if a child is waived up to adult court, where the state must prove intent or any other state of mind, a reasonable child standard should be applied in assessing culpability.

The reasonable child standard accounts for the innate differences of children's states of mind. A “reasonable child” standard considers how the characteristics typically associated with youth should be part of an analysis concerning the reasonability of a juvenile defendant’s conduct and mental state. Supreme Court precedent supports this separate standard because disparities between adolescents and adults stem from developmental differences, and science fully supports a treatment that differentiates immaturity in the criminal law context.

Adolescence spans from puberty until the mid-20s, and the term generally refers to the transitional period from childhood to adulthood. This time period signifies extreme changes and growth in the brain, including thinning of gray matter, increased growth in white matter, increased functional connections between regions and an overall lack of uniform development across regions of the brain, especially in the amygdala and frontal cortex. The amygdala is responsible for immediate reactions, like fear or aggression. Scientists determined that the frontal lobe acts as a “check” to the social-emotional system because it controls reasoning. However, some studies show that the frontal lobe finishes maturing around 30 years old, much later than other regions of the brain.

Due to structural differences in juveniles, they behave and think differently mainly because the “regions that seek reward are more active and mature earlier than the regions able to control impulses.” Adolescents engage in reward-seeking behavior not only for the perceived societal benefits, but also due to their sensitive dopamine systems seeking rewards. A study found that when compared to adults, juveniles focus more on rewards, and they find it difficult to avoid punishment or consider consequences. Further, emphasis on peer relationships and ongoing brain developments may cause juveniles to take more risks since they focus on social benefits and are unable to weigh consequences. This phenomenon also means that children are less likely to think before they act, adequately review decisions and consider the consequences of their actions, and change their dangerous or inappropriate behaviors. In fact, when compared to childhood, adolescence morbidity and mortality increase by 200%, which is largely due to the vulnerability of risky behaviors such as reckless driving, alcohol or drug consumption or violence.

The Supreme Court acknowledged this science and the legal differentiation between juveniles and adults in its 2011 decision in J.D.B. v. North Carolina, noting “that children characteristically lack the capacity to exercise mature judgment and possess only an incomplete ability to understand the world around them.” In numerous cases, the Court has noted that a child’s age is “more than a chronological fact;” it is a sign of the child’s lack of experience and mature judgment. These cases include Gall v. United States (2007), Roper v. Simmons (2005), and Johnson v. Texas (1993). Recent Supreme Court decisions in Roper v. Simmons (2005), Graham v. Florida (2010), and Miller v. Alabama (2012) emphasized how features of adolescence like impulsivity, sensation-seeking and susceptibility to peer influence collectively diminish juveniles’ culpability, making them ineligible for most severe forms of punishment. In short, the immaturity and poor decision-making the Court described in its holdings is the norm for adolescents and it is distinct from an adult’s understanding of risks and consequences. This is not to excuse children from culpability for their actions and the harm they cause, but rather to ensure that fact-finders assess adolescents’ culpability through a lens that differentiates their perception of risk and potential harm from that of adults.

States are beginning to pay attention to how children are different. For example, in Illinois, HB1064 abolishes life without parole for adolescents convicted of first degree murder. Bill sponsor Rep. Rita Mayfield said:

“Even when a crime is particularly severe, it should be recognized that a legal minor with their whole life still ahead has the potential to be reformed…However, in a nation like ours, prison should be a place where people have the opportunity to transform themselves and become better people and productive members of society. I believe that giving everyone a chance at redemption is a moral duty.”

This type of legislation has bipartisan support, and again, is backed by science. For example, Sen. Donald DeWitte said:

“I consider myself a law-and-order Republican, but I also believe in rehabilitation. I believe there are some people who make extremely poor decisions in the very early portions of their lives who deserve consideration once they have met benchmarks and shown they are prepared to become contributing citizens after they have served their debt to society. For these people, we need to offer them hope and let them know we recognize that people can redeem themselves.”

In fact, most children naturally grow out of delinquent behavior, with a study showing that “only a small percentage of young offenders escalate their behavior to committing crimes during adulthood.”

An integral part of criminal law is determining a defendant's state of mind. We have years of research in neuroscience, psychology and psychiatry determining that children are different. While the Supreme Court has come to terms with these differences in some of their decisions, as a blanket rule, it must be that a juvenile's immaturity, lack of decision making skills and impulsivity are considered in mens rea analysis. As stated by the Court in J.D.B. v. North Carolina, age “is a reality that courts cannot simply ignore.”

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