Another longitudinal study examined three theoretical models to explain substance use (Wills, McNamara, Vaccaro, & Hirky, 1996). The researchers followed a sample of 1,184 adolescents (47% female and 53% male) from upstate New York from 7th to 9th grades. Cluster analysis of the data of the ethnically diverse sample (37% Caucasian American, 29% African American, 23% Hispanic) showed that there were four subgroups: non-users, minimal experimenters, later starters, and escalators. Overall, psychosocial variables from 7th grade predicted substance use in 9th grade. Escalators (those who became frequent users) had high life stress, nonadaptive coping strategies, deviance-prone attitudes, parental and peer substance use, low parental support, low academic competence, and low behavioral control. The experimenters (those who had tried but were not frequent users of drugs) and late starters (those who started using drugs later in their childhood/adolescence) were moderate on these factors, while non-users were very low on the risk factors.