Research from Public Health Wales (2015) shows that compared to people with 0 ACEs, people with 4+ ACEs are:

  • 14x more likely to have been a victim of violence over the last 12 months
  • 15x more likely to have committed violence against another person in the last 12 months
  • 20x more likely to have been incarcerated at any point in their lifetime

The results of the ACE studies reinforce other theories of crime which have proven links between childhood adversity and adulthood criminality. Prolonged exposure to stress in childhood disrupts healthy brain development, which can manifest as emotional and conduct problems and later lead to risk-taking and criminal behaviour in adulthood.

Here are two case studies of prison facilities that have become much safer for staff and more effective at reducing challenging behaviour among prisoners.


Kearney Mesa Juvenile Detention facility, San Diego (US)

Adolfo Gonzales, San Diego’s chief probation officer, wanted to make the atmosphere of the city’s detention facilities “more therapeutic and rehabilitative.” The department he’d inherited was under fire for excessive use of physical force and pepper spray. There had also been 24 suicide attempts that year, up from 10 the year before.

The department opened a 20-bed “Trauma Responsive Unit” for young males at the Kearney Mesa Juvenile Detention facility. They designed it to be homelier and less institutional to help the young men stay calm, with brighter furniture, clouds painted on the ceilings, smaller classrooms and bedrooms with chalkboards for the inmates to draw or write on. They also provided a 4-hour training programme on the neurobiology of trauma to staff, with similar training also offered to the inmates themselves.

  • In the unit’s first year, 223 young men were placed in it. No violent incidents took place during that time, compared to 29 and 14 in two comparable units.

  • Inmates only made three suicide attempts, compared to 15 and 25 in the comparable units.

  • Half the inmates completed all four training sessions, with a 76% drop in trauma-related symptoms as a result.

  • Even those who took part in only one of the sessions saw a decline of 61%.


Massachusetts Correctional Institution, Framingham (US)

Framingham women’s prison underwent a trauma-informed transformation in the early 2010’s. This included a peer support programme to provide one-on-one and group support under mental health supervision; trauma-informed training for all staff; a new Intensive Treatment Unit (ITU); and various initiatives, including programmes for yoga and service dog training.

Soon after implementing these measures, the facility saw rapid improvements across a range of behaviours that have strong correlations with childhood trauma. In just one year between 2011 and 2012, they saw declines in the following areas:

  • Inmate-on-staff assaults: 62%

  • Inmate-on-inmate assaults: 54%

  • Inmate-on-inmate fights: 46%

  • Suicide attempts: 60%