It is common knowledge that much of what we learn originates from our experiences growing up. The way we speak, how we hold ourselves and our characteristics are all a product of the environment we grow up in and the people we interact with. According to Hermida; Hamlin (2006) “Criminal acts therefore arise from experiences along man's journey aggravated by many factors such as poverty, revenge and the likes and are most likely gained through interaction with other people.” (Differential Association Theory: Defining the Root of Violent Crimes," 2012, January 17). Much like students learn how to read and write from being around a teacher, Sullivant learnt how to behave like a criminal through being around Costello and the Mafia. Sullivans experiences …show more content…
Sullivan isn’t the only character in The Departed who becomes a product of his environment. Billy Costigan, an undercover cop in Costello's gang quickly develops criminal behaviour. Costigan is meant to be on the right side of the law, he is supposed to be one of the good guys in society. However he proves that if we are subjected to constant interaction with a group of people whom portray the ideals and values of a criminal we will soon replicate their behaviour and develop a criminal attitude. Costigan reverts to violence as a means of getting information about Costello's gang and progressively becomes more violent as he is subjected to further interaction with Costello's gang. The change in behaviour is explained through The Differential Association Theory which claims that, “Criminal behaviour is learnable and learned in interaction with other deviant persons.” (Edwin H. Sutherland,