In general, the NYS has lower rates than the three city surveys, reflecting the difference between a national sample and local samples drawn from urban areas. The differences may also reflect the timing of the studies. Another key difference between the national and city surveys is the maturation effect, or the age at which serious violence begins to decline sharply during the transition to adulthood. Therefore, it is too soon to tell whether or at what age more recent groups of youths will mature out of violence. It is possible that young people are staying violent longer.
Female adolescents have lower rates of serious violence throughout the second decade.
For the NYS and Denver surveys, rates at age 12 are about twice as high for boys as for girls. Between age 12 and 15 in Rochester, the rates are fairly similar. For all studies, the rates for females at age 17 are about one-quarter the rates for males. In addition, the peak age of serious violent offending occurs a few years earlier among females, and their maturation out of serious violence is both earlier and steeper than males'. The NYS finds a significant racial gap between ages 14 and 17, when rates for African American youths are 36 to 50 percent higher than those for white youths.