Abstract
Humans have behavioral adaptations to avoid sickness. While adults detect and avoid sick faces, less is known about how these abilities develop. This study examined sick face perception in a primarily U.S. sample of 57 4-5-year-olds (26 male, 70% White), 52 8-9-year-olds (29 male, 62% White), and 51 adults (30 male, 61% White), between 2021-2022. While 4-5-year-olds did not identify sick faces, 8-9-year-olds and adults did (ds = .93 and 1.95, respectively). When asked who they would sit next to, only adults avoided sick faces (d = 2.01). Sick face recognition ability emerged between 4 to 9 years of age but improved into adulthood. Characterizing children’s sickness avoidance may help reduce illness spread, ultimately improving child health.