The project from Southern Illinois University at Edwardsville will work to update instructional bioscience content in high-school curricula to increase accuracy and decrease sociocultural biases. The proposed project will increase our understanding of how biology instructional content can impact student bioessentialist beliefs and has the potential to contribute foundational knowledge about the epistemology of bioessentialist bias and the process by which these attitudes develop. There has been limited research into the mechanisms and tools within STEM education that can affect change in prejudicial fundamental attitudes and beliefs about sex, sexuality, and gender. The research instruments and curriculum materials developed as a part of this study as well as the findings will be of use to future practitioners, encourage future research on inclusive education, and create prospective tools for decreasing prejudicial beliefs and implicit biases. Mixed methods analysis will explore whether exposure to inclusive biology lesson plans can change the prevalence of gender essentialist, transphobic, or homophobic attitudes, change STEM and career interest, and whether any of these potential effects vary by student identity, especially for LGBTQ students.<br/><br/>The project plan includes supportive activities for the PI through an aligned professional development plan engaged through trainings, conferences, and the support of expert mentors. These advisors will assist the PI in attaining the skills needed for development as a STEM education researcher and scholar. The effort will be guided by a diverse group of credentialed educators and scientists working in accredited schools and universities. Dissemination will be addressed through communication in STEM professional pathways, including conferences, training, and publications. The project is supported by NSF's EDU Core Research Building Capacity in STEM Education Research (ECR:BCSER) program, which is designed to build investigators’ capacity to carry out high-quality STEM education research.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.