Scientist Versus Nonscientist: Identity, Threat, Derogation and Agreement with the Knowledge Deficit Hypothesis among STEM Students in the US

This journal article examines why the knowledge deficit hypothesis (KDH) remains popular in U.S. science communication despite substantial counterevidence. Using a survey of STEM college students in the United States, the study tests how social identity and perceived intergroup threat shape agreement with the KDH. Results indicate that identifying as a scientist was associated with being White, studying natural sciences, and being a graduate rather than an undergraduate student. A moderated-mediation analysis found that stronger ingroup (scientist) identification was linked to greater agreement with the KDH and greater derogation of nonscientists as ignorant or uninformed about STEM. Derogation partially explained the relationship between scientist identification and KDH agreement. These associations were stronger when students perceived nonscientists as posing a threat to science, and became insignificant when perceived threat was low or absent. Findings are discussed using social identity theory and intergroup threat theory.