Abdorrahman Boroumand Center

for Human Rights in Iran

Promoting tolerance and justice through knowledge and understanding
Death Penalty

Criminal Responsibility and Youth Offenders: A Neuroscientific View

Dr. Robert Griffith, Psy. D.
Abdorrahman Boroumand Center
March 30, 2019

Criminal Responsibility and Youth Offenders

Criminal responsibility or culpability in a crime does not have an international, uniform age or definition. In the United States, a person can be excused from criminal responsibility if criteria are met which can vary from state to state, with some states having no criteria. For example, the American Law Institute standard is as follows: “as a result of mental illness or mental defect [the individual] lacked substantial capacity either to appreciate the wrongfulness of his conduct or conform his conduct to the requirement of law.” According to Packer (2009), there are two critical words that are important in this definition: “appreciate” and “wrongfulness.” In adults, the impairment can be either in appreciation of wrongfulness or in the inability to conform conduct. The word “substantial” suggests that there is a significant degree of impairment, but not an absolute lack of ability (Packer, 2009).

There are also different ages at which charges can be brought against a person. In the United States, the lowest minimum age for which criminal charges can be brought is 7 (North Carolina) and the highest minimum age is 10 (Wisconsin). It should be noted that this varies internationally. For example in Peru, the age at which a person can first be criminally responsible is 18. If a person is under 18, it is considered “an infraction” and that youth is then “subjected to socio-educative measures, though these could include the deprivation of liberty.” Roughly the same criteria are applied in Brazilian law.

Cipriani (2012) notes the extreme variation in setting the minimum age for criminal responsibility for various regions of the world. He also states that “the level of MACR (minimal age of criminal responsibility) is not necessarily dictated by overall policy towards juvenile offenders.” For example, those countries that set a higher age for criminal responsibility may not afford youth the ability to present their case to a court; this is because they are not charged, but youth below the minimum age may have to go through administrative procedures, some of which may result in limiting their personal freedom or liberties, even though these administrative procedures are said to be educative.

Historically, courts around the world treated youth with a “welfare” approach rather than a due process one. Cipriani (2012) indicates that the change from the welfare-based to the due process approach occurred because of US Supreme Court cases in the 1960s such as Kent v United States and In re Gault. Criminal allegations against youth would now be heard in court. Cipriani (2009) states that there was a philosophical shift which meant that “offenders, once proven guilty, are held personally accountable for their actions. As such, there is significantly less focus on treatment and protection (for youth), while penal intervention becomes central.”

How is the age of criminal responsibility determined? There seems to be an arbitrary process involved. Cipriani (2012) writes:

Lawmakers ultimately encapsulate in one age, at one point in time, in a specific socio-political-cultural context, some batch of ideas about children’s capabilities and society’s expectations about children’s appropriate role. Upon that age, children may potentially bear criminal responsibility for their actions, and the state can first legitimately levy—in legal terms—criminal sanctions against them.

Delmage (2013) argues that maturity is an underlying factor that guides the decision regarding the minimum age of criminal responsibility, but the law has not been crafted to align with available neuroscience research. Delmage also notes that this idea of maturity is not always correlated with age: “A commonly discussed paradox is that an adult offender who, due to a learning disability, is functioning at the level of a ten-year-old would, in all likelihood, have a defense available to him or her, whereas a child offender of ten in all likelihood would not” (Delmage, 2013).

To sum, criminal responsibility generally indicates that the individual charged lacks a mental capacity at the time of the offense that would have been associated with recognizing right from wrong. Being excused from criminal responsibility means that the individual had a mental state at the time of the offense that led to a substantial deficiency or impairment in recognizing right from wrong. The age at which courts then begin to charge youth for criminal acts varies considerably around the world. Children at the threshold set by the state or country can be charged with a crime but, if the child does not meet the minimum age for criminal responsibility, interventions other than the court are typically used, if any interventions are made at all. Children who are not actually charged also cannot have a designated party argue their case in court. Yet, how is this age determined? For the most part, the age seems to be rather randomly assigned. Next, developmental neuroscience will be reviewed that may demonstrate how various issues involved with making such a decision have been explored. There does seem to be a disconnect between various juvenile sentencing practices and the research regarding how children’s and teenagers’ brain development impacts their decision making.

Part Two – Adolescent Brain Development

Even though in many aspects the minimum age for criminal responsibility seems to be randomly assigned, it should be noted that relevant developmental neuroscience has been taken into consideration in United States Supreme Court cases. For example, a brief submitted in the case of Miller v Alabama by the American Psychological Association, American Psychiatric Association, and National Association of Social Workers (2012) outlined research on the neuropsychological differences between adolescents and adults. The literature of these different groups submitted as evidence indicates that adolescents are different from adults based on immaturity, changeability, and vulnerability. Adolescents undertake four brain changes: increased myelination, synaptic pruning, increased connectivity to brain areas related to social and emotional processing, and incentive processing systems. The uneven distribution of changes in the adolescent brain influences their increased risk-taking and inability to self-regulate.

The neuroscience and social science submitted persuaded the court to rule in favor of Miller, who was sentenced to life in prison as a 14-year-old after he had been sentenced as an adult on charges related to capital murder in the course of arson. Justice Kagan, writing for the majority, said “Given all that we have said in Roper, Graham [other cases], and this decision about children’s diminished culpability, and heightened capacity for change, we think appropriate occasions for sentencing juveniles to this harshest possible penalty will be uncommon” (Miller v Alabama 2012).

Steinberg and Lamb (2017) argue the Supreme Court has increasingly utilized science, especially developmental science, in its rulings. After reviewing the four major Supreme Court cases over the past 12 years, they suggest further research is needed.

Years before MRI machines were developed, Peter Huttenlocher (for a summary, see his 2002 work) discovered that brain cell connections, or synapses, increased substantially during the first year of life. This is likely due to the massive amount of learning that takes place during that time period. Following these synaptic connections, there is a long period of synaptic “pruning” where these connections disappear.

Now, research has clearly demonstrated the adolescent brain is much different from the “adult” brain. The “adult” is in quotes because, despite the fact that 18-year-olds from around the world begin to take on many new responsibilities at that age, research indicates that neurological development continues at least until the age of 25. The concept of adolescence seems to suggest “autonomy.” Individuals at that age are typically given rights such as voting or can participate in the military.

A brain cell is called a neuron. We are born with most of the neurons we will ever have, but to learn, the brain needs to connect in a neuron-to-neuron manner. Those connections between neurons are called synapses. Everything that is learned results in such connections. In some places, such connections form early in life and in other places, later. “Studies carried out in the 1970s and 1980s demonstrated that the structure of the prefrontal cortex undergoes significant changes during puberty and adolescence” (Blakemore and Choudhury, 2006).

Myelination is the process by which axons that connect neurons together are coated. This process allows for increased speed and efficiency of sending signals through the axon. One clear example of a myelination problem is multiple sclerosis. Disruptions in a person’s functioning are present because of disruptions in the coating or myelination.

The prefrontal cortex appears to be the last area to be myelinated. This has implications for adolescent functioning. As the neuroscientist Robert Sapolsky (2004, more recently 2018) indicates: “The job of the frontal cortex (is) to bias individual towards doing the harder thing rather than the easier thing.” This would be the optimal function of the frontal cortex once myelination is complete in the frontal cortex area. The brain of the adolescent is “incomplete” because myelination processes are incomplete in the frontal area of the brain. This leads to an adolescent being less mature, more prone to impulse control problems, less able to plan ahead and more likely to be vulnerable to drugs and alcohol and their effect. Because of these neurocognitive vulnerabilities, a 13-year-old adolescent may do something on impulse (without thinking ahead or planning, or doing the right thing) that may impact his or her entire life course.

Other brain areas are involved in such impulse control functions, as well. Swartz and colleagues (2014) emphasized connections to the amygdala, which plays a strong role in emotional functioning. They looked at the uncinate fasciculusto (a white matter tract connecting the amygdala and the pre-frontal cortex) and the functional activity of the amygdala. This particular white matter or myelinated tract develops over the first three decades of life. The authors found an inverse relationship between structural connectivity and amygdala activation to sad and happy faces. This association was mediated by age, where younger children showed reduced connectivity and increased amygdala activation. This suggests that increased cognitive control plays an important role in regulating the amygdala and affective experiences. As adulthood develops, better control over emotional responses may be expected.

Pagpagno and colleagues (2011) reviewed the proposed function of this same communicating white matter tract and indicated that it develops in the areas of emotional and memory functioning. They studied surgical removal of this tract due to disease. Subjects in which the tract was resectioned in the frontal lobe area did substantially worse than controls on measures of face naming and verbal fluency. Thus, with the loss of this white matter tract, individuals exhibited frontal lobe symptoms.

Bradley and colleagues (2014) found that

in a unique sample of neurological patients that focal lesions involving ventromedial prefrontal cortex, acquired during development, result(ed) in an abnormally egocentric pattern of moral judgment. In response to simple hypothetical moral scenarios, the patients were more likely than comparison participants to endorse self-interested actions that involved breaking moral rules or physically harming others in order to benefit themselves.

Clearly cognitive decision-making and moral development proceed in a trajectory that continues at least until the third decade. A metanalysis by Defoe et al (2015) of experimental investigations of adolescent risk-taking suggests:

Adolescents engaged in more risk-taking than adults on tasks with immediate outcome feedback but not on tasks with delayed outcome feedback, consistent with the notion that the presence of outcome feedback (perhaps particularly on rewards) might trigger the hyper activation of the ventral striatum especially in adolescence, possibly resulting in heightened risk-taking behavior.

Noteworthy is the ventral striatum’s role in reward. Defoe et al (2015) discuss experiments in which adolescents took more risks while driving when their peers were present than they did when driving alone. They also note that fMRI studies have shown ventral striatum activity substantially increased when adolescents played a risky driving game with peers nearby than when they played the game on their own.

Kambam and Thompson (2009) review research by Steinberg (2008) about adolescent decision making. They indicate that research on the adolescent’s planning ahead and thinking about future outcomes is consistent with earlier studies and found that adolescents were less future-oriented than adults across all indices studied. The age differences that were noted did not vary by gender or ethnicity. Kambam and Thompson (2009) also review findings from the MacArthur study which included 1,400 adolescents ages 11 to 24. In this study, subjects were given a battery of tests to better understand legal decision making and capacity to assist counsel. As indicated by Kambam and Thompson, “juveniles aged 11–13 were more than three times as likely as young adults to be ‘‘seriously impaired’’ in their competence-related capacities and those aged 14–15 were twice as likely to be ‘‘seriously impaired.’’ Although IQ is important in looking at such capacities, the “serious impairment” is actually in concert with a kind of normative timetable of developmental maturity.

In an interesting paper which adopts perspectives from social psychology and criminology, Skrzypiec (2017) put forth a new approach to adolescent crime prevention using the theory of planned behavior. This theory takes into consideration three cognitive components. The attitude toward the behavior is important in this regard. For example, “a young person may see the outcome of stealing as a positive thing, as one will gain the object(s) stolen; or alternatively, as a negative thing, as one may face the consequences of getting caught.”

With regard to normative subjective beliefs, “a person may feel motivated to comply with the family’s expectations to not engage in dishonest actions or, alternatively, motivated to comply with the expectations of friends who are transgressors and co-transgress.” Another factor is perceived behavioral control. Some adolescents may believe stealing is something they may never do, while others may have more permissive attitudes.

Skrzypiec discovered that moral norms and reputation enhancement played an important, but distal part of fighting, stealing and drug use in adolescents she studied.

Finally, in a seminal paper on the importance of moral development when reviewing mitigation for capital crimes, Walker et al (2018), recommended that defense teams for adult defendants should review factors such as verbal intelligence, positing that moral norms are established through verbal reasoning skills. “Moral competence is shaped by the child’s whole environment during development, including the safety, security, parental affection and modeled behavior by the nuclear family.” In other words, the early shaping of moral competence is important. “Moral competence is not simply a given in human nature. It must be learned and it exists along a continuum from better to worse.” They consider evaluating empathy, sympathy, and compassion through evaluating the early environments of the client and the defendant’s training in moral competence. Walker and colleagues suggest that evaluating the adult defendant’s fetal exposure to substances and maternal stress in healthcare in addition to the postnatal environment “because all the brain regions involved in moral competence are highly sensitive to early adverse events and even early childhood depression.”

The findings of psychological and developmental neuroscience are taken into consideration and have great value for court systems around the world. Examples of juvenile justice systems will now be sampled.

Part Three - Juvenile Court Systems

First, diversion courts seem to take this research regarding brain development and behavior into consideration. Whether based on intuition (during the periods of welfare and therapeutic intervention) or changing ideologies (in the United States, the 1990s was such a period of change), it is clear that the history of juvenile justice in the United States moved from diversion and welfare considerations to retributive considerations in the 1990s. Even before the development of neuroscience and technical innovations such as MRIs or fMRI’s, progressive juvenile courts were using therapeutic interventions with a focus on restorative justice rather than retribution.

For example, regarding restorative (versus retributive) justice, Bishop and Decker (2008) comment,

Instead of focusing on the offender, these programs focus on the offense; on its effects on the victim and (with the exception of victim-offender mediation) the larger community of family and friends that support both victim and offender; and on apology, forgiveness, and reparation of harm. Broadly stated, the goals are to educate participants about the harms – especially the emotional harms and fracturing of relationships – caused by the offense; to repair the harms and to rebuild relationships and strengthen systems of informal social control. The establishment of restorative justice programs in the USA has not kept pace with similar developments in Western Europe, Australia, New Zealand, and Canada, though in some jurisdictions substantial progress has been made.

Second, there are countries such as Norway, Sweden, and Austria that have based their programs on diversion rather than retribution. In these countries, the age of criminal responsibility is 15. Below this age, youth are not subjected to prosecution, but social interventions are put in place. Storgaard (2005) notes “in all Scandinavian countries [Denmark, Finland, Norway, and Sweden,] crime prevention efforts have a high priority and are to some extent acknowledged as just as important as prosecution.” She indicates that the likelihood of “obtaining lower recidivism among juveniles via training programs is improved under the following conditions: when the treatment is concentrated on offenders who are at real risk of re-offending; when the treatment is intensive; when the treatment’s form and content is closely connected to the concrete situation and when the treatment is fulfilled without deprivation of liberty.”

In Austria, much emphasis is placed on prevention of delinquency, beginning in the preschool years and continuing into late adolescence and early adulthood. For example, during leisure time, many adolescents meet at parks for recreation and in the past, there appears to have been delinquent behaviors between different ethnic groups. However, monitoring by adults has been largely successful as a preventative measure. Such preventative measures make neurological sense: the adults that provide monitoring are presumed to have myelinated frontal lobes (and thus maturity) that can help supervise and manage problem areas and conflicts before adolescents get into trouble with the police (Bruckmüller, 2008).

Additionally, a diversion from court is common for adolescents in Canada. The Youth Criminal Justice Act provides for this. Bala and Roberts (2008) write that

In some communities in Canada, minor violent offences, such as assaults in schools are dealt with by extrajudicial sanctions programs that, for example, may involve victim-offender reconciliation or family group conferencing, and may result in an apology to the victim, personal service orders, restitution, community service or counseling for the offender (Bala and Roberts, 2008).

It seems that all youth diversion types of interventions seem to have a component of teaching, rehabilitative efforts, and an implicit idea that adolescents and adults differ significantly. This significance has a basis in developmental neuroscience, whether these types of programs acknowledge it or not.


This paper reviewed the notion of criminal responsibility and it's diverse and seemingly random age assignment in various juvenile courts around the world. By no means was the review of developmental neuroscience in this paper complete. However, the best programs from this developmental perspective, do utilize the well-researched idea that adolescents and adults are different. In the 20th century, until the 1960s and 1970s, researchers believed that brain development was static after the early childhood years. This has radically changed. In this article, programs were illustrated that are not focused on retribution, but more focused on diversion or community monitoring. These programs seem to parallel or may be modeled after research in child and adolescent neuroscience.



Bala, N and Roberts, J (2008) Canada’s Juvenile Justice System: Promoting Community-Based Responses to Youth Crime. In International Handbook of Juvenile Justice Punishment and Control: Decker, S and J Junger-Tas (editors), Springer

Bishop, D and Decker S (2008) Punishment and Control: Juvenile Justice Reform in the USA, In International Handbook of Juvenile Justice Punishment and Control: Decker, S and J Junger-Tas (editors), Springer

Blakemore, S, and Choudhury (2006). Development of the adolescent brain: implications for executive function and social cognition. Journal of Child Psychology and Psychiatry 47:3 (2006), pp 296–312

Bradley, C., Taber-Thomas, Erik W. Asp, Michael Koenigs, Matthew Sutterer, Steven W. Anderson, Daniel Tranel. Arrested development: early prefrontal lesions impair the maturation of moral judgment. Brain, Volume 137, Issue 4, 1 April 2014, Pages 1254–1261

Brief for the American Psychological Association, American Psychiatric Association, and National Association of Social Workers as Amici Curiae In Support of Petitioners, Miller v. Alabama, 10-9646, Jackson v. Hobbs, 10-9647, 2012 (See below for citations used in the case)

Bruckmüller, K (2008) Austria; a protection model, in International Handbook of Juvenile Justice Punishment and Control: Decker, S and J Junger-Tas (editors), Springer

Cipriani, D. (2012). Children's rights and the minimum age of criminal responsibility: A global perspective. Farnham, Surrey: Ashgate.

Costanza Papagno, Christiano Miracapillo, Alessandra Casarotti, Leonor J. Romero, Lauro Antonella. Castellano Andrea, Falini Giuseppe Casaceli, Enrica Fava, Lorenzo Bello. What is the role of the uncinate fasciculus? Surgical removal and proper name retrieval Brain, Volume 134, Issue 2, 1 February 2011, Pages 405–414

Defoe, I., Dubas, J., Figner, B., Van Aken, M., & Albarracín, Dolores. (2015). A Meta-Analysis on Age Differences in Risky Decision Making: Adolescents Versus Children and Adults. Psychological Bulletin,141(1), 48-84.

Delamge, E (2013) The Minimum Age of Criminal Responsibility: A Medico-Legal Perspective: Youth Justice 13(2) 102–110

Hooper, S. M., & Chiong, W. (2018). Decision-making capacity and frontal lobe dysfunction. In B. L. Miller & J. L. Cummings (Ed.). The human frontal lobes: Functions and disorders (3rd ed., pp. 184-199). The Guilford Press New York, NY

Huttenlocher, P. R. (2002). Neural plasticity: The effects of environment on the development of the cerebral cortex. Cambridge, MA: Harvard University Press.

Kambam and Thompson (2009) Development of decision-making capacities in children and adolescents: psychological and neurological perspectives and their Implications for juvenile


Rankin, K. P., Gola, K., & Jerard, T. L. (2018). Socioemotional functioning and frontal lobe injury. In B. L. Miller & J. L. Cummings (Ed.). The human frontal lobes: Functions and disorders (3rd ed., pp. 200-216). The Guilford Press New York, NY

Sapolsky, R (2004) The frontal cortex and the criminal justice system Philos Trans R Soc Lond B Biol Sci. 2004 Nov 29; 359(1451): 1787–1796.

Sapolsky, R (2018) Behave: The biology of humans at their best and worst.Penguin Books

Skrzypiec, G. (2017). Adolescents’ Intentions to Engage in Criminal Activity: A Cross-Disciplinary Approach Linking Theories From Social Psychology and Criminology. Journal of Forensic Psychology Research and Practice,17(5), 305-337.

Steinberg, L., & Lamb, Michael E. (2017). Adolescent brain science and juvenile justice policymaking. psychology, Public Policy, and Law, 23(4), 410-420.

Swartz, Carrasco, Wiggins, Thomason, & Monk. (2014). Age-related changes in the structure and function of prefrontal cortex–amygdala circuitry in children and adolescents: A multi-modal imaging approach. NeuroImage, 86, 212-220.

Van Duijvenvoorde, A., & Crone, E. (2013). The teenage brain: A neuroeconomic approach to adolescent decision making. Current Directions in Psychological Science, 22(2), 108-113.

Walker, R., Clark, J. J., Monahan, E. C., Shechet, A., Agharkar, B. S., Kheibari, A., & Iii, G. V. (2018). Developmental impairments in moral competence as mitigation in capital cases. Behavioral Sciences & the Law,36(4), 437-456.

Werchan, D., Amso, D., & Holyoak, Keith J. (2017). A novel ecological account of prefrontal cortex functional development. Psychological Review, 124(6), 720-739.