Evaluation for both

• Harer and Steffensmeirer analysed data from 58 US prisons, including importation variables like race as well as situational variables like security levels.

  It was found that importation variables were significant predictors of prison violence.

  Supports importation and does not support deprivation
• Poole and Rergoli found juvenile delinquents the best predictor of inmate aggression was pre-institutionalised violence

  Supports importation and does not support deprivation
• De lisi found prisoners with prior street gang involvement were not more likely than others to behave aggressively in prison. This could however be explained by the fact that prisons tend to isolate gang members from other prisoners.

  This might explain why we do not always see aggressive behaviour from pre-prison gang members in the prison iteself.

  Supports deprivation
• Much of the research into prison aggression focusses on male inmates so it may be androcentric.

  The model may not therefore be a valid explanation of institutional aggression in female prisons
• McCorkle looked at 371 state prisons in the US and found that factors such as overcrowding, lack of meaningful activity and lack of privacy significantly influenced inmate assaults on both other inmates and staffs

  Supports deprivation