Based on the research0 of Martín Sánchez-Jankowski, what are the primary reasons

According to sociologist Martín Sánchez-Jankowski, boys in urban areas are motivated to join gangs for a number of reasons.  After following gangs of all types for over ten years, Sánchez-Jankowski found that the motive for boys joining a gang was not because of living in a broken home or seeking a substitute family, but rather to gain access to money, to have recreation (girls and drugs), to maintain anonymity in community crimes, to get protection, and to help the community. In some of the neighborhoods, gangs protect residents from outsiders and the boys saw the gang as an alternative to the dead end, which they considered jobs held by their parents