Make it a habit: how habit strength, goal importance and self-control predict hand washing behaviour over time during the COVID-19 pandemic

Hand washing has been at the core of recommendations and guidelines that aim to curb infectious diseases in general, and COVID-19 in particular. As hand washing comes down to an individual's behaviour, we aimed to study how individual psychological variables influence hand washing over time during the COVID-19 pandemic.

Over the course of 20 weeks, participants answered questions about their hand washing behaviour, goal importance, habit strength and self-control. Participants from an experimental and a control condition completed a baseline and final measurement, and the experimental condition was invited to bi-weekly measurements through reminders.

Hand washing behaviour over the past 14 days was assessed by self-report at baseline and final measurement, and additionally repeatedly over the course of 20 weeks in the experimental condition.

Hand washing behaviour decreased over time, but this decrease was buffered by habit strength and goal importance. The decrease was smaller in the experimental condition that received reminders every 2 weeks.

Sending personal reminders on hand washing behaviour contributes to hand washing behaviour. Moreover, taking habit strength and goal importance, and to a lesser extent self-control into account is important when designing interventions to promote hand washing behaviour.