PERSPECTIVES ON GANGS : Deference to Gangs Makes Them Kings of the Roost The tragic death of 3-year-old Stephanie Kuhen allegedly at the hands of the Avenues gang has spawned Mayor Richard Riordan's announcement of a countywide Street Gang Working Group to quell gang violence. MALCOLM W. KLEIN, director of social science research at USC, has studied street gangs for 23 years. Based on personal experience and bolstered by statistics from police and court files, Klein wrote the newly published "The American Street Gang" (Oxford University Press). He argues that society's attempts to abate gangs has inadvertently reinforced gang cohesion and violence. and * As told to Joseph Hanania, Special to The Times