Children’s understanding of the causal mechanisms underlying disease prevention

Abstract

What drives children’s early beliefs about disease transmission and prevention? We taught children (N = 152; 3;0–7;11) about three ailments (COVID-19, a novel disease Zerpox, bike-related injury) and the Personal Protective Equipment (PPE) used to prevent them (facemasks, earmuffs, helmets). Children then saw pairs of characters and decided who was safer from [getting sick/hurt]. In a preregistered 2x3x2 within-subjects design, we manipulated whether each character wore PPE or not, whether they wore the correct PPE for the ailment, and whether they wore the PPE properly. Children displayed stronger knowledge of PPE for preventing injury than illness, although there were large age effects. Performance on COVID-19 trials was generally similar to Zerpox trials, suggesting similar reasoning about novel and more familiar diseases. We classified children’s performance based on the folk theories that might underlay their behavior, showing a strong reliance on theories other than germ theory in shaping performance.