As the COVID-19 pandemic lingers, the possibility of ‘pandemic fatigue’ has raised worldwide concerns. Here, we examine whether there was a gradual reduction in adherence to protective behaviours against COVID-19 from March through December 2020, as hypothesized in expectations of fatigue. We considered self-report behaviours from representative samples of the populations of 14 countries (N = 238,797), as well as mobility and policy data for 124 countries. Our results show that changes in adherence were empirically meaningful and geographically widespread. While a low-cost and habituating behaviour (mask wearing) exhibited a linear rise in adherence, high-cost and sensitizing behaviours (physical distancing) declined, but this decline decelerated over time, with small rebounds seen in later months. Reductions in adherence to physical distancing showed little difference across societal groups, but were less intense in countries with high interpersonal trust. Alternative underlying mechanisms and policy implications are discussed.

随着 COVID-19 大流行的持续，“大流行疲劳”的可能性引起了全世界的关注。在这里，我们检查了从 2020 年 3 月到 12 月，针对 COVID-19 的保护行为的依从性是否如疲劳预期所假设的那样逐渐减少。我们考虑了来自 14 个国家（N = 238,797)，以及 124 个国家的流动性和政策数据。我们的结果表明，依从性的变化在经验上是有意义的，并且在地理上广泛存在。虽然低成本和习惯性行为（戴口罩）的依从性呈线性上升，但高成本和敏感行为（物理距离）下降，但这种下降随着时间的推移而放缓，在随后的几个月中出现小幅反弹。保持身体距离的减少在社会群体之间几乎没有差异，但在人际信任度高的国家中并不那么强烈。讨论了替代的潜在机制和政策影响。