• There are over 21,500 gangs in the United States.
• The vulnerability for joining gangs is highest among youths from 13-15 years and decreases thereafter.
• California has the most gang cities of any state in the U.S.
• 47% of all gang members were Hispanic
• 31% of all gang members were African-American
• 13% of all gang members were white
• 7% of all gang members were Asian.
• Individual risk factors for joining gangs:
  • Delinquent peer network.
  • Commitment to negative peers.
  • Lack of parental supervision.
  • Favorable attitudes about breaking the law.
• Reasons gang boys gave for joining a gang:
  • Protection.
  • Have a territory.
  • Feel a sense of belonging.
  • Get money or other things.
  • Friend was a member.
  • Family member had joined.
  • Feel important.
  • Do illegal activities.
• Five types of gangs:
  • Traditional – Large size (>100). Sub-groups with long existence and are territorial.
  • Neo Traditional – Medium size (>50). Sub-groups with short existence and territorial.
  • Collective – Medium size (>50). No sub-groups, medium existence and non-territorial.
  • Compressed – Small size (<50). No sub-groups, short existence, non-territorial.
  • Specialty – Small size (<50). No sub-groups, short existence, territorial.
• Social Factors leading to gang involvement:
  • Lower school performance.
  • Lower impulse control.
  • Higher recorded delinquency.
  • More often truant.
  • Fewer outside interests.

*According to Malcolm W. Klein & Cheryl L. Maxson (2006).