This study explores how antisocial behavior among adolescents at age 14 is related longitudinally to their daily smoking, heavy alcohol use, and illicit drug use (hashish and amphetamines) at age 17. The sample of 9th graders (n = 1293) attending compulsory schools in Reykjavik, Iceland participated in the study and in the follow-up 3 years later. The focus is on a subgroup of 17-year-old adolescents who had not experimented with cigarette smoking, alcohol consumption, or illicit drug use at age 14. Even after eliminating from the study those who had experimented with smoking at age 14 and those whose peers smoked, the adolescents who showed more signs of antisocial behavior at age 14 were more likely to smoke daily at age 17. Similar findings were revealed for illicit drug use at age 17. Further, with regard to alcohol use, adolescents who had not experimented with alcohol but showed indications of antisocial behavior at age 14 were more likely to drink heavily at each episode at age 17 if their parents drank.
Based on a psyschosocial developmental framework, this study used a mixed model design, including both quantitative and qualitative methods, to examine the relationship between adolescents' psychosocial maturity and their alcohol use. A sample of 1,198 10th-grade students (51% female) was surveyed and followed up two years later. Both concurrent and longitudinal findings indicated that the more psychosocially mature adolescents were less likely to drink heavily than those who showed less maturity. At age 15 this relationship was even stronger for those whose peers also drank. Further, at age 17, this linear relationship was more pronounced for those who drank less heavily at age 15. Of the three psychosocial competencies examined, the construct of personal meaning was more strongly related to adolescent alcohol use than were the constructs of interpersonal understanding and interpersonal skills. To illustrate this construct, two of the adolescents were interviewed, a girl and a boy, individually at the end of both school years. Thematic and developmental analyses of the interviews revealed individual variations in how the adolescents made meaning of their drinking; these encourage speculations that go beyond the general pattern found in the study.
Adolescents' perceptions of parenting style and parental involvement in their education were examined longitudinally and related to school dropout among Icelandic youth (N = 427). Results indicated that adolescents who, at age 14, characterized their parents as authoritative (showing acceptance and supervision) were more likely to have completed upper secondary school by age 22 than adolescents from non-authoritative families, controlling for adolescents' gender, socioeconomic status (SES), temperament, and parental involvement. Parenting style seems to more strongly predict school dropout than parental involvement. Further, parenting style may moderate the relationship between parental involvement and dropout, but not in all groups; only in authoritative families does parental involvement decrease the likelihood of school dropout. Furthermore, even after controlling for previous academic achievement, adolescents from authoritative families were less likely to drop out than adolescents from authoritarian and neglectful families. These findings emphasize the importance of encouraging quality parent-child relationships in order to reduce the likelihood of school dropout.