By James McGuire

The occurrence of violent assault in prison is a challenging problem. This Analytical Summary reports the findings of a rapid evidence assessment (REA) into the causes of physically violent assaults by male adult prisoners. The REA reviewed 97 research studies published since 1st January 2000. Key findings • Most of the published research is focused on imported characteristics – the personal characteristics of men who are violent in prison – and attempts to predict who they will be. Imported characteristics associated with prison violence include youth, history of earlier violence in prison or with violent convictions, membership of gangs, low self-control, anger, temper, mental health problems, and antisocial attitudes and personality. • The prison environment also plays a considerable role in how prisoners behave. Physically poor conditions, highly controlling regimes, or by contrast circumstances in which rules are unevenly applied or not adhered to or where prisoners do not experience staff decisions as fair or legitimate, can each heighten tensions and induce stresses potentially giving rise to conflict and assault. • Perhaps surprisingly, evidence that crowding in and of itself was a direct cause of violence was fairly weak. Research suggested that the effects of crowding are mediated through staff-prisoner interactions and that the crucial factor in maintaining order is the availability and the skills of unit staff. • Some features of prison activity make violence less likely. Places within a prison where prisoners are engaged in purposeful activities they consider valuable, such as workshops and education, are less prone to be sites of aggression. Violence is more likely to occur in places that offer less purpose, have fewer formal ground-rules, and lower staff oversight, such as cells. • A policy designed to reduce violence could be oriented towards situational control aspects of day-to-day prison management. That would require staff training in the use of styles and patterns of interaction that wield authority alongside instilling respect.

London: HM Prison and Probation Service, 2018. 9p.