The cause of institutional aggression is the prison environment itself
Harsh conditions are stressful for inmates so they resort to aggressive behaviour to cope
These conditions include deprivation of freedom, goods and services, safety and heterosexual intimacy
This leads to competition for goods amongst inmates
Aggression is also caused by the nature of the regime
Unpredictable lock ups create frustration, reduces stimulation and leads to aggression
Aggression becomes an adaptive solution to deprivation
Supporting Evidence - Steiner et al
Investigated factors that predicted inmate aggression in 512 American prisons
Found that inmate-on-inmate violence was more common in prisons where there were higher proportions of female staff, African-American inmates, Hispanic inmates and inmates in protective custody for their own safety
These are all prison-level factors because they are independent of the individuals characteristics
The factors reliably predicted aggressive behaviour in line with the deprivation model
Supporting Evidence - Cunningham et al
Analysed 35 inmate homicides in Texas prisons and found that motivations for the behaviours were linked to some of the deprivations identified by Clemmer
Particularly important were arguments over drugs, homosexual relationships and personal possessions
Contradictory Research - Hensley et al
Studied 256 male and female inmates in two prisons in Mississippi a state that allows conjugal visits
There was no link between these visits and reduced aggressive behaviour