Social-emotional learning (SEL) of students has been the focus in K-12 for many years. Recently, the impact of SEL on teachers has become important to universities and educational systems across the world. Teachers spend significant time with students. Teachers must create a positive and caring relationship for students to be academically and socially successful. "Positive teacher-student relationships lead to increased cooperation and engagement in the classroom" (Nishioka, 2019, p 1). Teachers have a lifelong and lasting impact on students. The purpose of this quantitative difference study was to examine if teachers' years of experience with SEL influence student academic achievement. There were two schools that participated in the quantitative difference study. The study also determined while implementing teaching practices, if there is a statistically significant difference or if there is no statistically significant difference between teachers with high and low understanding of the SEL competencies--self-awareness, self-management, social awareness, relationship skills, and responsible decision making. The study participants were selected through purposeful and convenience sampling from two middle schools in southeastern Virginia and completed a modified online survey called the "Self-Assessing Social and Emotional Instruction and Competencies: A Tool for Teachers" (American Institutes for Research, 2014) and a demographic survey to collect data. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]