Knowing when to doubt: a measure of epistemic vulnerability to scientific disinformation

Scientific disinformation poses a challenge for public understanding of science, yet the psychometric assessment of epistemic dispositions underlying vulnerability to misleading scientific claims remains underdeveloped. This study introduces and validates the Epistemic Vulnerability to Scientific Disinformation Scale across six samples from Peru, Kenya, Nigeria, Uganda, and the United States (total N = 4,932). Exploratory and confirmatory factor analyses across samples yielded a 12-item unidimensional scale encompassing source and credibility analysis, evidence evaluation, logical reasoning, and contextualization of scientific information. The final scale showed satisfactory factorial validity, internal consistency, and configural and metric invariance across samples. Construct validity was supported by theoretically consistent associations with epistemic beliefs, attitudes toward science, fake news detection, vaccine hesitancy, climate change denial, familiarity with scientific concepts, and overclaiming. The scale provides a concise and psychometrically robust measure of epistemic vulnerability to scientific disinformation.