What is the Delinquent Subculture Theory by Albert Cohen?

In 1955 Albert K. Cohen wrote "Delinquent Boys." The summary of his theory is that in the slums of the cities subcultures (culture within a culture) form with values that oppose the dominant cultures. These subcultures are considered delinquent subcultures. They often act on impulse and their delinquent acts serve no real purpose.