This study focused on the ability to experience a high ratio of positive to negative emotions in 807 Israeli adolescents aged 12 to 15 years (50% girls). While considering possible gender differences, we tested a model positing that adolescents’ self-control skills would link to their positivity ratio and indirectly through perceived social support from parents and classmates. Parental support was significantly higher than classmate support, and girls scored significantly higher than boys on self-control skills and on both support sources. Self-control skills linked directly with positivity ratio and indirectly through parents’ and classmates’ support, with no gender differences found for the overall model. The study highlights the importance of prevention and treatment programs designed to impart adolescents with prosocial self-control skills, to improve their perceived availability of social support and consequently to increase their positivity ratio during this intense developmental period.