As used in this study, "self-determination" refers to making decisions and taking action based on personal choices, interests, and motivation from within oneself rather than in response to directions from another person. This study found that autonomy-supportive parental teaching was significantly related to children's self-determination in school performance and job-seeking behaviors, and it was positively linked to measures of adjustment in various areas of social activity. Self-determination was an intervening variable in the link between perceived social functioning and adjustment in adolescence. These findings stemmed from two studies. The first study focused on the degree of self-determination in both school and peer activities. The sample consisted of 328 adolescents (74 percent boys and 26 percent girls) from 2 secondary schools (grades 10-12) in the Dutch-speaking part of Belgium. The questionnaires measured parental autonomy-support compared with psychological control, teachers' autonomy support, self-determination, social and scholastic competence, and grade-point average. The second study focused again on the development of self-determination in school, but also examined behaviors related to searching for a job. These behaviors were linked to the characteristics of interactions with parents and teachers. The second study involved a sample of 285 adolescents from 3 secondary schools in the Dutch-speaking part of Belgium. All participants were in the last grade of high school. 2 tables, 3 figures, and 76 references