The inflexible mind: A critical factor in understanding and addressing COVID-19 vaccine hesitancy

Background: Vaccine hesitancy has gained heightened relevance amid the COVID-19 pandemic, underscoring the urgency of understanding its determinants. This study explores the association between Covid-19 vaccine hesitancy, mental health variables and inflexible thinking. Methods: A convenience sample of 252 UK adults was assessed online between June 2021-July 2022 (when Covid-19 lockdown restrictions had finally eased). We assessed participants using the Oxford Covid Vaccine Hesitancy Scale (OCVHS), various aspects of mental health, using: the Obsessive-Compulsive Inventory-Revised (OCI-R), Compulsive Personality Assessment Scale (CPAS), Depression, Anxiety, and Stress scale (DASS-21), and finally, performance on a computerized version of the Wisconsin Card Sort Task (WCST). This study was preregistered at the Open Science Framework (https://osf.io/xd5wz). Results: Multiple regression analyses showed that only cognitive inflexibility, and specifically the WCST item of perseverative errors, significantly predicted vaccine hesitancy. Conclusion: Our exploratory analysis provides the first evidence that cognitive inflexibility, measured using an objective task, is an independent risk-factor for vaccine hesitancy. Public health strategies should consider the impact of an inflexible thinking style on the decision-making of those most at risk of vaccine hesitancy and adapt interventions accordingly.