The aim of this study was to reveal whether religiosity and trust in institutions are longitudinal predictors of change in fear of COVID-19 (FCV-19) across Poland, Germany, Slovenia, and Israel among young adults over a three-month period. The representative sample consisted of 1723 participants between the ages of 20 and 40 years (M = 30.74, SD = 5.74) across Poland (n = 446), Germany (n = 418), Slovenia (n = 431), and Israel (n = 428). The first measurement was carried out in February 2020 and the second was conducted in May/June 2020. A repeated-measures, two-way, mixed-factor ANOVA was performed to examine changes over time (T) and across countries (C) as well as the interaction of time and country (TxC) for FCV-19, religiosity, and trust in institutions. The results showed a significant decrease over time and differences between countries in all variables, as well as in TxC for FCV-19 and trust in institutions. Linear generalized estimating equations (GEEs) were used to assess the longitudinal change between T1 and T2 in FCV-19, including religiosity and trust in institutions as predictors, country as a factor, and gender and age as confounders. Female gender, religiosity, and trust in institutions were found to be significant longitudinal predictors of change in FCV-19. Country was a significant moderator of the relationship between trust in institutions and FCV-19, with the highest result achieved in Poland. Religiosity and trust in institutions were positive predictors of change in fear of COVID-19 among young adults across countries. Religious and governmental institutions should take this into consideration when communicating with believers and citizens during challenging situations.
Keywords: a longitudinal study design; fear of COVID-19; religiosity; trust in institutions; young adults.