Because most blacks grow up in dangerous neighborhoods and they feel trapped there so gangs give them a cool feeling like they belong and are a part of something so they join. But most can't get out and many don't ever think about the consequences of being in a gang. Gangs give underprivledged kids a chance or a purpose for their life
They grew up in the projects.
I didn't realize it was mostly blacks. I realize there aren't a lot of white gangs, but there are quite a few Latino ones. Where I live it is minorities who for one reason or another are led to believe that even if they do work hard in school and get an education that they will never receive a fair shake in a white dominated world.
Or some are taught they if they do get an education that they are giving into the "white ways". Others still just don't want to work for anything. They think it is easier to just take from others.
Normal Nobody is correct.
Also - a gang is just a group of people joined together for a common cause. The structure of criminal gangs isn't that different from that of civic organizations (Elks, Eagles, Etc).
As to why ANYBODY joins a gang ... Sociologists say it's because the gang fulfills the need for family and human interaction.