About the author
Dr Nathan Hughes is Senior Lecturer in the School of Social Policy at the University of Birmingham. He is also Marie Curie Research Fellow at the Centre for Adolescent Health and the Australian Centre for Child Neuropsychology Studies at the Murdoch Children’s Research Institute, Melbourne, and Visiting Senior Fellow at the Melbourne School of Government, University of Melbourne. Through these parallel roles, Dr Hughes is undertaking a programme of research concerned with the application of advances in neuroscience to law and social policy. In particular, his research considers the explanations apparent in emerging understandings of neuromaturation of patterns of offending among young adults and those with neurodevelopmental impairments, and explores the implications of these emerging understandings for policy and practice within the criminal justice system.
Reason for the submission
A research review examining ‘Maturity, young adults and criminal justice’ (Prior et al, 2011), co-authored by Dr. Hughes and published by the Transition to Adulthood Alliance, is cited as instructive in the committee’s decision to focus on provision for young adults. Given the perceived high relevance of this research, it is timely to provide an update of the evidence in relation to maturity and offending. Dr Hughes was also lead author of ‘Nobody Made the Connection’ (Hughes et al, 2012), a report published by the Children’s Commissioner for England, examining the prevalence of neurodevelopmental disorders among young people in custody. Subsequently he led a systematic review of research examining the pervasiveness of traumatic brain injury among offending populations. This research has recently been used in support of policy and practice reform in the UK and New Zealand.
This submission therefore reflects on recent advances in understandings of:
In both instances the implications for criminal justice policy and practice are considered. This enables reflections on the questions posed by the Terms of Reference of the Inquiry, particularly regarding:
Terminology
In defining young adulthood, there is considerable debate regarding terminology and associated age ranges. For the purposes of this submission, such terminology is employed in keeping with dominant use within the developmental science research literature.
Adolescence is therefore defined as the period between the ages of 10 and 24.
Late adolescence is used interchangeably with young adulthood to refer to the distinctive phase of development occurring between the ages of 18 and 24 (SAHRC, 2013).
Neuromaturation refers to the functional development of the brain and other aspects of the central nervous system.
Neurodevelopmental impairments are physical, mental or sensory functional difficulties caused by disruption in the development of the nervous system. Such difficulties include: cognitive deficits; specific learning difficulties; communication difficulties; affective or emotional deficits; and related behavioural problems.
1. Executive summary
Neuromaturation in young adulthood
1.1 Young adults are physiologically different to older adults, and more akin to younger adolescents in key aspects of their maturation.
1.2 Late adolescence is a dynamic phase of functional brain development towards the ‘adult form’, particularly regarding the maturation of emotional and affective functioning.
1.3 For young adults, rational decision-making may not always be exercised effectively under stressful or emotionally charged circumstances. Young adults may favour immediate benefits over future rewards or risks, and be particularly susceptible to peer influence.
1.4 There is significant heterogeneity in the timing of processes of neuromaturation, and this can be positively or negatively influenced by social context and experience, prior to and during adolescence.
Implications for criminal justice policy and practice:
1.5 A graduated approach to criminal justice should recognize young adults as developmentally distinct from young people (under 18) and older adults (over 24), and provide a bespoke response accordingly.
1.6 Assessments of young adults should seek to understand the maturity of thinking and emotional functioning, as well as analyzing the ‘maturity of the offence’.
1.7 By adopting a developmental approach to young adult justice, specific stages of neurobiological and psychological development can be responded to, and maturation can be recognized as a developmental concept that can be altered through support and intervention.
1.8 Effective practice with young adults requires specialist knowledge and understanding.
Neurodevelopmental impairment among young adult offenders
1.9 Neurodevelopmental impairment affects typical processes of neuromaturation. Symptoms and expressions of neurodevelopmental impairment have a direct influence on offending behaviour, including cognitive and emotional deficits, and communication difficulties.
1.10 Neurodevelopmental impairment is highly prevalent among young offenders. This disproportionate prevalence is also likely among young adult offenders due to the continued relevance of symptoms and expressions of impairment to life course persistent offending behaviour, and the associated challenges in following typical pathways to desistence.
Implications for criminal justice policy and practice:
1.11 Routine screening and assessment of neurodevelopmental impairment should be undertaken for all young adults in custodial or community justice settings, so as to enable responsive support and inform specialist service commissioning.
1.12 Generic criminal justice interventions that do not recognize impairment are unlikely to be effective in addressing the causes of offending. Instead specialist approaches must be developed and employed.
1.13 Criminal justice practitioners should be aware of issues related to neurodevelopmental impairment and adjust their practices accordingly.
2. Neuromaturation in young adulthood
In summary, research evidence shows that:
2.1 Adolescence is a particularly dynamic period of brain development, second only to infancy in the extent of developmental change that is occurring within neural systems. It is increasingly recognised as a key phase of functional brain development towards the ‘adult form’, with key processes of neuromaturation not completed until early adulthood. Of particular relevance here is the asynchronous processes of cognitive and affective development, and the associated influence on emotional maturity. It is well recognised that by mid-adolescence young people generally demonstrate similar cognitive capacities to adults, in terms of their ability to understand and retain information, and to recognize the risks associated with particular behaviours. However, emotional and affective functioning is understood not to be fully developed until late adolescence. There are three processes that determine this differential development:
2.2 (1) Brain regions associated with emotions, rewards and desires - known as the limbic regions - develop in association with hormonal changes during puberty. As a result, adolescent decision-making can be particularly dominated or motivated by reward incentives.
2.3 (2) In contrast, regions within the prefrontal cortex are ‘among the last areas of the brain to mature; they may not be fully developed until halfway through the third decade of life’ (Johnson et al 2009: 216). This area of the brain is associated with a range of traits and functions of relevance to offending behaviour, including impulse control, the regulation of emotion, problem solving, long-term planning, and understanding and weighing up the consequences of particular courses of action. As Johnson and Geidd (2015: 1728) explain: ‘It is not that these capabilities are absent during the teen years, but they are not as good as they are going to get.’
2.4 (3) Adolescence is also the period in which connectivity between regions of the brain is greatly improved. This occurs through a process of sheathing of neuronal axons with myelin, a substance that insulates neural pathways and facilitates more efficient transmission of information and integration of brain activity, improving information processing. Emotional maturity (the ability to regulate and interpret emotions) is associated with the establishment of robust connections between the cognitive processes of the prefrontal cortex and the emotional processing performed by the limbic regions. However, current evidence indicates that in the prefrontal cortex myelination does not occur until the stage of young adulthood, meaning cognitive and emotional integration ‘continues to develop well into adulthood’ (Johnson et al, 2009: 217-8).
2.5 Evidence of these neurodevelopmental changes can help explain the ways in which adolescents might process information and make decisions differently from adults in particular social contexts, including those in which offending typically takes place. The following paragraphs offer several specific implications.
2.6 Behavioural science research has repeatedly shown that in emotionally or socially charged contexts, adolescents take greater risks than do adults. Adolescent inhibitory control appears susceptible to being ‘overcome under emotional circumstances’ (Spear, 2013: 7). This means that, while the capacity for rational decision making reaches adult-typical levels by mid-adolescence, this capacity may not be exercised under ‘stressful, emotionally charged, and arousing circumstances’ (Spear, 2013: 10) – what are referred to as situations of ‘hot cognition’. Some prevalent forms of offending behaviour occur under such circumstances, including those related to impulse or reactive aggression.
2.7 Divergence between cognitive understanding of risks and consequences and risk-taking behaviour is thought to be related to the way in which the still-developing adolescent brain appears to be governed by the limbic system so as to emphasise emotional and social aspects of decision-making and to favour short-term rewards over longer-term outcomes. In particular, the adolescent may weigh the benefits of certain forms of behaviour, which may include achieving social status or peer acceptance, more strongly than they do the knowledge that the decision may have negative consequences, including a criminal record that might affect future prospects. The risks and benefits of any decision may therefore be assessed differently by an adolescent than an adult; more pertinently an individual’s decision-making processes and preferences are likely to naturally change as they mature into an adult.
2.8 A related body of work has established age-related changes in temporal discounting: the inclination in adolescence to discount the value of future rewards as compared to immediate ones. This tendency declines across this period, as the balance and connectivity between the limbic and frontal regions of the brain is altered, and seems to represent the main way in which adolescent decision making deviates from mature, adult-like decision making.
2.9 A further notable way in which adolescent decision making is different from that of adults is the weight adolescents assign to peer influence when making decisions – a factor known to be important to many offending related decisions during adolescence. This may be related to the desire for immediate short-term rewards associated with peer acceptance. However studies also suggest that the development of resistance to peer influence is likely to be related to the way the brain regulates its own responses to the non-verbal emotional displays of others – a higher executive function developed during this period through the prefrontal cortex.
2.10 Clearly such generalised explanations of neuromaturation mask significant heterogeneity in timing and processes of brain development. Determining factors are not well understood, but are likely to include a complex range of biological, social and environmental factors (Giedd, 2008, Dahl, 2008), aligned with those known to serve as risk factors for offending. In particular, there ‘is a growing recognition that social contexts strongly influence how these neural systems develop and how adolescents make decisions.’ (Crone and Dahl, 2012: 637) Indeed Crone and Dahl (2012) present this life stage as a period of ‘experience-influenced sculpting’ of the brain. This suggests the potential role of socioeconomic factors, and past experience. Of course, many of the young people within the criminal justice system are known to be affected by adverse life circumstances that may influence neuromaturation, including difficult family, social and environmental contexts. It also suggests the importance of ongoing experience during mid and late adolescence in supporting neuromaturation and emotional maturity.
Implications for criminal justice policy and practice
2.11 Understanding neuromaturation as a continuing process through early adulthood suggests that the age of 18 is an arbitrary cut-off point for immediately treating young adults with the full force of the adult criminal justice system, and instead calls for a distinct approach that is aware of and responsive to variation in maturity among this age group. Indeed, there is increasing international recognition that differentiated approaches should be applied to young adults, with many jurisdictions developing bespoke systems for those aged 18 to 24 (Dünkel and Pruin, 2010, Pruin and Dünkel, 2015).
2.12 For many young adults, offending behaviour may continue to be affected by issues of emotional control, impulsivity, reactive aggression, and peer influence. Assessments should therefore adopt a developmental perspective, taking account of aspects of maturity apparent in the young adult’s thinking, emotional functioning and behaviour. This should include determining whether the offending behaviour is juvenile in nature, suggesting issues with immaturity that should be addressed in sentencing.
2.13 For example, in Germany maturity is assessed through an analysis of both the offender and the offence, with youth justice interventions applied if a lack of maturity is demonstrated. Juvenile law can be applied to young adults if the ‘moral and psychological development’ of the defendant suggests he or she is ‘like a juvenile’. This might include a lack of emotional maturity or empathy. Similarly juvenile law is applied if ‘the motives and the circumstances of the offence are those of a typical juvenile crime’ (Dünkel, 2004: 23); for example, if it is carried out under the influence of peers, or if it is linked to the use of alcohol. Such an approach is therefore closely aligned to understandings of adolescent emotional development, susceptibility to peer influence and emotional response to social stimuli.
2.14 A developmental approach to working with young people ‘recognizes that how children and youth perceive, process and respond to situations is a function of their developmental stage, and secondarily their culture and life experience.’ (SFY, 2015) Understandings of the ‘specific, sequential stages of neurological and psychological development’ during adolescence (SFY, 2015) are utilised so as to support ‘prosocial development’ through interventions ‘tailored to the particular adolescent’s needs and social environment’ (Bonnie et al, 2012: 11).
2.15 By adopting a developmental perspective, interventions with young adults can acknowledge and support processes of neuromaturation - and certainly not act counter to them. Maturity-informed practices can address aspects of functioning that appear immature, including emotional regulation, impulse control and peer influence, and therefore support better, more mature decision-making. Young adults with delayed neuromaturation may be diverted to more appropriate youth justice interventions.
2.16 Recognition of the specific processes of neuromaturation occurring for this age group can lead to more effective means to support desistance. Utilising desistance theory can inform specific interventions looking to build on positive developmental changes occurring for the young adult, such as the forming of adult relationships, future aspirations, or reduced drug use. By utilising desistence theory, interventions can target those processes of maturation known to have the greatest influence on reducing offending behaviour in this age range.
2.17 Professionals and practitioners working in all aspects of the criminal justice system must recognise that young adults may typically be distinct from older adults in their thinking and behaviour, and modify their practice and modes of engagement accordingly. This suggests the need for specific training in working with young adults within a developmental framework, and/or for specialist staff roles within police, court and probation services.
In summary, research evidence shows that:
3.1 Whilst recognising significant individual variability, the research reviewed in the previous section broadly examines typical neuromaturation processes. In contrast, significant proportions of young people within the criminal justice system are affected by childhood neurodevelopmental impairments that influence such maturation.[1]
3.2 Childhood neurodevelopmental impairments are physical, mental or sensory functional difficulties caused by disruption in the development of the brain or other aspects of the nervous system. Such functional difficulties include: cognitive deficits; specific learning difficulties; communication difficulties; affective or emotional deficits; and behavioural problems. This broad range of impairments are commonly experienced as one or more clinically defined neurodevelopmental disorder, such as: learning disability; specific learning disorders; communication disorders; attention deficit hyperactivity disorder (ADHD); and autistic spectrum disorder (Patel, et al, 2011; APA, 2013).
3.3 It is clear that experiences of neurodevelopmental impairment increase the likelihood of involvement with the criminal justice system. Cognitive, emotional and behavioural traits that are symptomatic of neurodevelopmental impairment can give rise to the expression of aggressive or antisocial behaviour in particular social situations, therefore increasing vulnerability towards criminality (Hughes, 2015). For example:
3.4 The potential for the criminalisation of those with neurodevelopmental impairment due to the failure of systems and services to recognise and respond to their impairment is also increasingly clear (Hughes, 2015). This includes restricted access to justice through inappropriate use of forensic interviewing and a lack of engagement with court procedures, and the use of unsuitable and therefore ineffective interventions and practices.
3.5 A wealth of research demonstrates the disproportionate prevalence of neurodevelopmental disorders among young offenders, when compared to the rates among young people in the general population. This is particularly apparent in studies of young people in custodial institutions, as evidenced in two recent reviews of research (Hughes et al, 2012; 2015), summarised in the following table:
| Prevalence among young people in general population | Prevalence among young people in custody |
Learning disability | 2 - 4% | 23 - 32% |
Communication impairment | 5 - 7% | 60 - 90% |
ADHD | 1.7 – 9% | 12% |
Autistic Spectrum Disorder | 0.6 – 1.2% | 15% |
Any head injury | 24 – 42% | 49 – 72% |
Head injury resulting in loss of consciousness | 5 - 24% | 32 - 50% |
3.6 It is clear therefore that significant proportions of young people in custody have one or more neurodevelopmental disorder. What’s more, this is likely to be an underestimate of the proportion of young people whose functioning is significantly affected by particular symptoms or sub-clinical levels of impairment.
3.7 Much less is currently known about the prevalence of neurodevelopmental impairment among young adult offenders; however, studies which examine this age range continue to demonstrate a disproportionate prevalence. Furthermore, a range of evidence would suggest that the disproportionate prevalence is likely to be maintained:
3.8 (1) Developmental psychopathology research demonstrates that symptoms and expressions of childhood neurodevelopmental impairment continue into adulthood. This can include difficulties with a direct influence on risk of offending, including impulse control, social communication, cognitive empathy, theory of mind, self-regulation of emotion, and so on.
3.9 (2) Modelling of the relative risk of life course persistent offending emphasises risk factors associated with specific neurodevelopmental impairments, particularly cognitive deficits.
3.10 (3) There is evidence of the ineffectiveness of generic youth justice interventions to support rehabilitation and prevention of reoffending among young people with neurodevelopmental impairment, including in relation to continuation of support in the transition from community to custody and vice versa, suggesting a greater risk of continued offending into adulthood.
3.11 (4) Theoretical models explaining processes of desistance emphasise transitional processes and markers into adulthood and maturity that are likely to be challenging for young adults with particular impairments, including entering the workforce, and forming stable and committed loving relationships.
Implications for criminal justice policy and practice
3.12 Whilst neurodevelopmental impairment will rarely be the sole cause of offending behaviour, without recognition of an underlying impairment its influence on offending behaviour cannot be understood and responded to, ensuring a failure to fully address the causes of criminality.
3.13 Screening and assessment will enable responsive individual support, able to address underlying cognitive difficulties and emotional needs. Screening will also identify collective levels of need so as to support commissioning of specialist health, education and employment services for young adult offenders.
3.14 The increased recognition and improving practice in the UK with regard to young offenders with neurodevelopmental impairment has informed the universal use of the Comprehensive Health Assessment Tool in all custodial institutions, and increasingly in community youth justice settings, so as to assess for a range of neurodevelopmental disorders (Chitsabesan, et al, 2015). Universal screening for neurodevelopmental impairment should be extended to all young adult offenders in custodial and community settings. This would be supported by information sharing between youth and adult justice systems – including of previous CHAT assessments.
3.15 Access to support within the criminal justice system that is responsive to specific needs and learning styles, and utilises practices known to be effective with people with specific impairments so as to address the underlying needs and vulnerabilities, appears rare. Instead those with neurodevelopmental impairment are typically subject to generic interventions which typically assume normative levels of verbal and cognitive competence, including the ability to reflect on and change thinking and behaviour. Such approaches may therefore be inappropriate for those with neurodevelopmental impairment, leading to difficulties engaging with and completing court orders.
3.16 In addition, cognitive deficits can lead to a misunderstanding of the rules of bail conditions, and therefore failure to adhere to them. If aware of an impairment, a court might offer greater support whilst on bail and avoid excessive use of breach procedures for repeated minor failures to comply with bail conditions.
3.17 It is also apparent that short-term interventions are typically not effective with young people with neurodevelopmental impairment. This is particularly clear in relation to short-term custodial interventions, given there is often no continuation of care from the community into custody, or from custody into the community.
3.18 Bespoke young adult criminal justice responses should enable the continuation of effective, specialist support utilised in the youth justice system. Whilst there remains a need for significant further reform and enhancement of the recognition and support of young people with neurodevelopmental impairments in the youth justice system, there are examples of promising practice that can be utilised with young adults, including the introduction of a Linkworker programme in two youth justice custodial institutions, supporting young people with traumatic brain injury through bespoke interventions and training of relevant staff (Chitsabesan, et al, 2015).
3.19 Such advances are not mirrored in the responses to young adults within the criminal justice system. There must therefore be concern that advances in recognition and support of the causes of offending among young people with neurodevelopmental impairment may be lost as these vulnerable young people transition into an adult system that does not assess or respond to such developmental needs. This period of transition in young adulthood is key to enabling desistence and preventing life course persistent offending.
3.20 Neurodevelopmental impairment can impact upon engagement in the criminal justice system in a number of ways, including when subject to forensic interviewing, particularly when asked to tell a story non-chronologically, and in following complex formal court procedures that adopt technical language. An awareness and understanding of the relevance of atypical neuromaturation to young adult offending suggests that professionals and practitioners working across the criminal justice system need to recognize and understand issues relating to neurodevelopmental impairment so as to address barriers to access to justice or potential criminalisation.
3.21 Awareness of neurodevelopmental impairment supports the development of policing and criminal justice practices that do not assume cognitive and communicative competence or understanding of procedures, and therefore support better engagement and access to justice, whether an impairment has been formally diagnosed or not. This should include:
References
Adolescent neuromaturation
Bonnie, R., Johnson, R., Chemers, B., and Schuck, J. (2013) Reforming juvenile justice: A developmental approach. Washington, DC: National Academies Press.
Crone, E.A. and Dahl, R.E. (2012). Understanding adolescence as a period of social–affective engagement and goal flexibility. Nature Reviews Neuroscience, 13, 636-650.
Dahl, R. E. (2008) Biological, developmental, and neurobehavioral factors relevant to adolescent driving risks. American Journal of Preventive Medicine, 35(3): S278-S284.
Dünkel, F. (2004). Juvenile Justice in Germany: Between Welfare and Justice. Paper at the European Society of Criminology conference, Lausanne. Available online: http://esc-eurocrim.org/files/ch09.pdf
Dünkel, F. and I. Pruin (2010). Young adult offenders in the criminal justice systems of European countries. F. Dünkel, J. Grzywa, P. Horsfield and I. Pruin. (eds) Juvenile Justice Systems in Europe: Current Situation and Reform Developments, Vol. 4. Monchengladbach: Forum Verlag Godesburg. Pp.1557-1580.
Giedd, J. N. (2008). The teen brain: Insights from neuroimaging. Journal of Adolescent Health, 42, 335-343.
Johnson, S. B., Blum, R. W. and Giedd, J. N. (2009) Adolescent maturity and the brain: the promise and pitfalls of neuroscience research in adolescent health policy. Journal of Adolescent Health, 45(3), 216-221.
Johnson, S.B. and Geidd, J.N. (2015) Normal Brain Development and Child/Adolescent Policy in Clausen, J. and Levy, N. (eds) The Handbook of Neuroethics, Dordrecht :Springer, pp.1721-1735. Available online: http://link.springer.com/referenceworkentry/10.1007/978-94-007-4707-4_148
Prior, D, Farrow, K, Hughes, N, Kelly, G, Manders, G, White, S, and Wilkinson, B (2011) Maturity, young adults and criminal justice: A literature review. London: Transition to Adulthood Alliance / Barrow Cadbury Trust. Available online: http://www.t2a.org.uk/wp-content/uploads/2011/09/Birmingham-University-Maturity-final-literature-review-report.pdf
Pruin, I. and Dünkel, F. (2015) Better in Europe? European responses to young adult offending. London: Transition to Adulthood Alliance. Available online: http://www.barrowcadbury.org.uk/wp-content/uploads/2015/02/T2A_Better-in-Europe_Report-_online.pdf
Spear, L.P. (2013) Adolescent Neurodevelopment. Journal of Adolescent Health 52: S7–S13
State Adolescent Health Resource Center (SAHRC) (2013) Understanding Adolescence: Late Adolescence. Available online: www.amchp.org/programsandtopics/AdolescentHealth/projects/Documents/SAHRC%20AYADevelopment%20LateAdolescentYoungAdulthood.pdf
Strategies for Youth (SFY) (2015). Philosophy « Strategies for Youth. [online] Available at: http://strategiesforyouth.org/about/philosophy/ [Accessed 3 Sep. 2015].
Neurodevelopmental impairment
Hughes, N., Williams, H., Chitsabesan, P., Davies, R. & Mounce, L. (2012) Nobody Made the Connection: The prevalence of neurodisability in young people who offend. London: Office of the Children’s Commissioner for England. Available online: https://www.academia.edu/7349196/Nobody_Made_the_Connection_the_prevalence_of_neurodisability_in_young_people_who_offend
Patel, D.P., Greydanus, D.E., Omar, H.A. & Merrick, J. (eds.) (2011) Neurodevelopmental Disabilities: Clinical Care for Children and Young Adults. New York: Springer. Available online: http://www.sxf.uevora.pt/wp-content/uploads/2013/03/Patel_2011.pdf
American Psychiatric Association (APA) (2013) Diagnostic and statistical manual of mental disorders (5th ed.). Washington DC: APA. Available online: http://www.dsm5.org/
Hughes, N. (2015) Neurodisability in the youth justice system: recognising and responding to the criminalisation of neurodevelopmental impairment, Howard League for Penal Reform, What is Justice? Series, Available at: https://www.academia.edu/15237699/Neurodisability_in_the_youth_justice_system_recognising_and_responding_to_the_criminalisation_of_neurodevelopmental_impairment
Hughes, N., Williams, W.H., Chitsabesan, P., Walesby, R., Mounce, L.T.A. and Clasby, B. (2015) ‘The Prevalence of Traumatic Brain Injury Among Young Offenders in Custody: A Systematic Review’, Journal of Head Trauma Rehabilitation, 30(2): 94-105. Available online: https://www.academia.edu/11345460/The_Prevalence_of_Traumatic_Brain_Injury_Among_Young_Offenders_in_Custody_A_Systematic_Review
Chitsabesan, P., Lennox, C., Williams, H., Tariq, O. and Shaw, J (2015) Traumatic Brain Injury in Juvenile Offenders: Findings From the Comprehensive Health Assessment Tool Study and the Development of a Specialist Linkworker Service. Journal of Head Trauma Rehabilitation, 30(2): 106-115.
30 September 2015
[1] Whilst it is beyond the scope of this submission, a similar argument might be made in relation to young people who have experienced abuse, severe neglect, or prolonged periods in institutional care, including youth justice custodial institutions.