assumes when individuals commit crime and receive a custodial sentence, they enter prison with traits or learned behaviours
e.g. inmates may have a pro-crime attitude, and a variety of criminal experiences
inmates also have personal characteristics such as race, gender, class or religious beliefs
Irwin and Cressey propose it's these attitudes and traits that make some inmates likely to continue with criminal behaviours and violence once they're inside prison
Offends important these antisocial behaviours into prison, and use them to navigate their way through their sentence and to deal with conflicts that may arise with other prisoners