Weeding out the Truth: A Survey Experiment on the Role of Scientific Evidence in Shaping Public Opinion on Marijuana Policy

Purpose: This study aims to explore the extent to which different forms of scientific research on the criminogenic effects of marijuana use impact public opinion on marijuana-related policy issues. Methods: We conducted an experimental priming survey using Qualtrics, targeting heads of households in South Carolina with associated email addresses. Multiple OLS regression models were employed to analyze single-item and aggregate scores of our dependent variables. Results: Our findings reveal that, except for the policy regarding the immediate release of a convicted offender, scientific research on the criminogenic effects of marijuana use did not significantly or substantively influence public perceptions of cannabis policies. Factors such as perceptions of police legitimacy, legal orientation, trust in law enforcement, and conservative or moderate political inclinations were significantly correlated with various outcomes. Conclusions: Respondents primed with research suggesting a link between marijuana use and an increased likelihood of engaging in violent and property crimes were more inclined to disapprove of releasing non-violent cannabis offenders from incarceration. However, exposure to scientific research generally did not influence participants' support or disapproval of other policies promoting the liberalization of marijuana-related policies. The study also discusses potential research and policy implications.