What is Optimism

This chapter aims to test the positive change in students' sustainable behavior that is expected to be found under the influence of relevant subjects. Therefore, a simple quasi-experimental design was applied to test the differences between those groups of students who have not taken the subject Pedagogy of sustainable development and those who have. Since studies for primary school and preschool teachers at the Faculty of Teacher Education, University of Rijeka, Croatia are designed for building needed competencies in future educators, the case study was expected to determine statistically significant differences between those groups of students who have taken relevant subject and those students who have not. Finally, correlation analyses were run for relationship between life satisfaction, optimism, and sustainable behavior to be analyzed. Based on previous research studies and theoretical models, it was expected to determine significant positive relationship between students' sustainable behavior and their levels of life satisfaction and optimism. Both hypotheses are confirmed in this study. All findings are discussed in this chapter within theoretical models and future study guidelines. The results confirm the usefulness of the course Pedagogy of sustainable behavior within higher education of future educators, and its influence within positive change in their sustainable behavior. Besides, the expected positive relationship of life satisfaction and optimism with sustainable behavior was confirmed and so provided a platform for creating a suggestion of implementation of the interdisciplinary course/subject of Pedagogy of Sustainable development and Positive psychology.