Intellectual disability in young people in custody in New South Wales, Australia - prevalence and markers.
Half of youth entering custody in NSW have borderline or lower IQ, with Aboriginal teens and those with psychosis at highest risk.
01Research in Context
What this study did
Researchers checked the IQ scores of every young person entering custody in New South Wales, Australia. They also noted who was Aboriginal, who had psychosis, and who had been locked up before.
The team wanted to know how many kids had borderline or lower IQ and what put them at risk.
What they found
Almost half of the youth scored in the borderline or lower IQ range. Aboriginal youth were three times more likely to fall into this group.
Early arrest and having psychosis also raised the risk.
How this fits with other research
Herrington (2009) saw only 11 % of young male prisoners in the UK with borderline IQ. The new NSW number is four times higher. The gap comes from different cut-offs: V counted only IQ 70-74 plus low adaptive scores, while Koegel et al. (2014) included anyone at borderline or below.
Dougherty et al. (1996) found just 0.33 % of Sydney adults had ID. Youth in custody show ID rates more than one hundred times higher, showing custody is not a mirror of the general community.
Duker et al. (1996) warned that people with ID are easy crime targets. L et al. flip the lens: the same group is also over-represented among offenders.
Why it matters
If you work in juvenile justice or transition services, expect that every second teen may need simplified language, visual aids, and step-by-step instructions. Screen intake with a quick IQ tool and add adaptive checks for those who score low. Flag Aboriginal youth and kids with psychosis for extra support. These steps can cut re-offense and make your behavior plans stick.
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02At a glance
03Original abstract
BACKGROUND: Intellectual disability (ID) is known to be more common in incarcerated groups, especially incarcerated youth. Aboriginal young people have higher rates of ID, and make up half of all youth in juvenile custody in New South Wales (NSW), Australia. We aimed to describe the prevalence of possible ID and borderline intellectual functioning (BIF) in young people in NSW custody, and to describe the association between possible ID and Aboriginality after adjusting for the inequalities in social disadvantage. METHODS: Baseline study of all youth in NSW Custodial Centres between August and October 2009, with 18-month follow-up. Using Wechsler Intelligence Scale for Children - Fourth Edition (WISC-IV) and Wechsler Adult Intelligence Scale - Fourth Edition (WAIS-IV) cognitive assessments, possible ID was defined as Extremely Low Intellectual Quotient range (Full Scale Intellectual Quotient, FSIQ < 70), and possible BIF was defined as Borderline IQ range (FSIQ < 80). Risk factors for possible ID and BIF included age, gender, Aboriginality, socio-economic disadvantage, offending history and psychological disorders. RESULTS: N = 295 (65%) of all young people in NSW custody completed cognitive and psychological assessments (87% male, 50% Aboriginal, average age 17 years). Almost one half (45.8%) of young people had borderline or lower intellectual functioning (by IQ assessment), and 14% had an IQ in the extremely low range (FSIQ < 70), indicating a possible ID. Aboriginal participants were three times more likely than non-Aboriginal participants to have a possible ID, but after accounting for the excess disadvantage in the Aboriginal group, Aboriginality was no longer a marker of ID. Incarceration from a young age and psychosis were significantly associated with possible ID in Aboriginal participants, compared with Aboriginal participants first incarcerated at a later age, and Aboriginal participants without psychosis. CONCLUSION: The inequalities in criminal justice between Aboriginal and non-Aboriginal youth may exacerbate or contribute to the intellectual impairment of those incarcerated from a young age. Aboriginal young people with psychosis are also at high risk of cognitive impairments that might indicate a possible co-morbid ID, and these patients should be diverted at court into community assessment services, rather than incarcerated. These results highlight a need for better and earlier identification of young people (particularly Aboriginal youth) at risk of ID and other co-morbidities in the juvenile justice system.
Journal of intellectual disability research : JIDR, 2014 · doi:10.1111/jir.12109