Relationship between emotional regulation difficulties and aggression in forensic populations: a systematic review; and, An empirical study examining the mediating roles of emotional regulation and hostile attribution bias in the relationship between traumatic brain injury and violent offending
CHAPTER ONE: SYSTEMATIC REVIEW: High levels of violence and aggression are observed in forensic populations. Difficulties with emotional regulation (ER) may be a risk factor for aggression. This systematic review summarized research examining the relationship between ER difficulties and aggression in individuals who offend. A systematic search of three electronic databases revealed twelve studies which were for eligible for inclusion. Seven of the studies found moderate associations between global ER and/or ER subscales and aggression. A group with adaptive ER had lower levels of aggression compared to those with maladaptive ER, and ER was found to be a potential mediator in the relationship between factors such as low self-esteem, post-traumatic stress syndrome, psychopathy, traumatic brain injury, alexithymia and aggression. Studies were consistent in identifying an association between ER and aggression in forensic populations. Future research should include longitudinal studies of ER and aggression, and further investigations should be conducted into the effectiveness of ER skills training in addressing aggression in forensic populations. CHAPTER TWO: EMPIRICAL STUDY This empirical study aimed to ascertain if emotional regulation (ER) difficulties and/or hostile attribution bias (HAB) played a role in explaining the relationship between having a history of traumatic brain injury (TBI) and engaging in violent offending. Eighty-two male offenders completed three questionnaires relating to TBI, ER and HAB, and consented to their offence history being accessed for research purposes. Results indicated that prevalence of TBI was extremely high in this prison setting at a rate of 96.3%. Mild TBI was most prevalent at 61% and, moderate and severe TBI accounted for 9.7% of the sample. The main source of TBI was assaults accounting for 48%. No significant differences were found between ‘no TBI’ and ‘TBI’ groups in relation to ER difficulties, HAB and offending behaviour. No significant relationships were found between TBI severity, ER, HAB and violent offending. Neither ER difficulties nor HAB mediated the relationship between TBI and violent offending in this offender population. Further research of this nature is needed to explore the relationship between TBI and criminality, specifically, looking at potential causal mechanisms as this remains unclear.