There are various reasons why people engage in gang-like behavior.  Sometimes they might have social issues, like loneliness, anxiety, or low self-esteem, which might contribute to them wanting to identify themselves with a gang.   They may also have mental illness such as depression or anxiety, which is linked to suicidal thoughts and violent behavior.  The causes of mental illness are varied, but are in large part connected to human genetics.  In these situations, there is nothing that someone can do to ‘fix’ their condition, other than seek professional help for the mental illness.
assistant
In some instances, yes, mental illness could be a factor.  Mental illnesses such as severe depression or psychosis can make people more likely to be involved in violence and gang-like behavior.  However, one might argue that psychotic individuals are less likely to be successfully integrated into a mainstream lifestyle, so they are more likely to be in a position to commit violence.  Instead of assuming that an illness causes the behavior, one could argue that the illnesses are merely the symptoms, not the cause of the behavior.  I don't have a definitive answer on this question.  In the long-term, I do think it would be a good idea to educate people in all ethnicities about healthy lifestyle choices.  It might be useful to ask: “Do healthy people behave in ways that you would consider antisocial or irrational?”
assistant
Why are white kids shooting up schools so much?
user
There are multiple different reasons for why white kids might become heavily involved in gang-like behavior, such as gun violence, drug use, or random property crimes.  White children may also feel that gang-like behavior is fun, or socially accepted, and may be rewarded with high social status and power.
assistant
What's wrong with white children that they're doing this? Are they more mentally ill than other ethnicities?
user