When belief meets the blackboard: Uncovering pseudoscientific ideas and misconceptions in Spanish pre-service teachers

• Although Education students moderately reject pseudoscientific ideas, there are some pseudoscientific beliefs and misconceptions that persist among pre – service teachers, especially in the Biology and Geology areas. • Master’s Program in Secondary Education Teaching students demonstrated greater critical thinking than Early Childhood and Primary Education Degree students, showing lower acceptance levels to false statements. • Statements belonging to the health domain (especially those about vaccines) obtained the lowest overall mean scores, indicating that students—both Master’s and Education Degree —are more critical in this category compared statements in other areas. • Our results support the relevance of establishing strong scientific foundations across all pre-university educational stages. This reinforcement will promote useful critical thinking skills to pre – service teachers, preventing the transmission of conceptual inaccuracies and pseudoscientific beliefs to their future students. Pseudoscientific beliefs and misconceptions are still spreading widely in society, often supported by social media and a lack of scientific literacy. This research focus on analyzing the degree of acceptance of such ideas among pre-service teachers at the Universidad Complutense Madrid (UCM), considering their academic level and pre-university educational background. A total of 492 students from undergraduate and Master’s programs in Education and Teacher Training participated in the study. Participants completed a questionnaire consisting of 30 statements representing common misconceptions and pseudoscientific claims across five scientific domains: health, geology, nutrition, biology, and multidisciplinary sciences. Our results show moderate rejection of pseudoscientific ideas by pre-service teachers, with the lowest acceptance levels found in the health domain. However, higher acceptance rates were observed in geology, biology, and nutrition items. Statistically significant differences were found between undergraduate and Master’s students, with the latter—mostly trained in scientific disciplines—exhibiting stronger critical thinking. Likewise, students with a background in science in pre-university studies demonstrated greater critical skepticism toward pseudoscientific claims. These findings highlight the importance of strengthening scientific basis and critical thinking skills in teacher education programs to prevent the propagation of pseudoscientific beliefs in classrooms and promote evidence-based education.