This paper examined the effects of teachers' preconceptions of social and emotional learning (SEL) after professional development training and continuous support. The COVID-19 pandemic exacerbated a disconnect between teachers and students, particularly in positive school climates. A positive school climate can help students to want to attend school, resulting in academic achievement and lower absenteeism. A positive school climate can lower stress in students and teachers and help teachers to feel empowered and want to continue in the profession. Social and emotional training and support seem to help in creating a positive school climate. This research addressed the question, can continuous social and emotional professional development and support change teachers' preconceptions and create a positive school climate? This mixed-methods study evaluated whether SEL training and support changed teachers' preconceptions. Quantitative data were collected via a survey designed by CASEL. Qualitative data were collected in interviews to answer open-ended SEL questions. This research used quota sampling to ensure that four middle schools in the CTSD were represented. Use of convergent-parallel methods ensured validity and reliability of the research. The results of the survey, interviews, and literature review indicated positive changes in teachers' preconceptions over time with the continuous use of SEL training and support. Triangulation of the data ensured validity. The results contain rich data and quotes from teachers who reflected on changes in their preconceptions. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]