The combination of parent and peer factors as they relate to substance use has been explored by Jessor, Van Den Bos, Venderryn, Costa, and Turbin (1995). They sought to test a model of developmental change in which the environment is considered to be dynamic with multiple factors working in concert. The project included a sample of 1,591 seventh-, eighth- and ninth-grade students (36% Caucasian American, 22% African American, 4% Asian American, 2% Native American) who were followed over a three year period. The students were asked about their protective environment (e.g., their parents and their peers) as well as their own personality and prosocial behaviors; both are considered to be protective factors for the youth. The findings support a model in which environmental and personal protective factors moderate the effects of risk (deviant and negative peer and parent models) on adolescent problem behaviors; the fewer protective factors that are in place, the greater the effect the risk factors will have on deviant behaviors such as drinking and using drugs.