Intra-group aggression among prisoners: bullying intensity and exploration of victim-perpetrator mutuality.

A new multiple indicator method of assessing bullying behaviour is employed (Direct and Indirect Prisoner behaviour Checklist - Scaled version [DIPC-SCALED]) with 605 adult prisoners (487 men and 118 women). The study explores if the DIPC-SCALED is a reliable method comprising of identifiable aggression factors; if prisoners can be classified into groups based on behavioural frequency; and if there is evidence for mutual victim/perpetrator groups. The DIPC-SCALED proved reliable, comprising of a number of aggression factors. Prisoners could be classified into groups based on behavioural frequency with one-fifth classified into an "intense" perpetrator and/or victim group. Evidence for mutual perpetrator/victims was found. Results are discussed with regards to the method used and the value in accounting for behavioural frequency in group classification.