The low prevalence effect in children

Low prevalence search tasks occur everyday and are characterized by targets occurring infrequently across repeated searches. This phenomenon, termed the low prevalence effect (LPE), refers to observers' reduced likelihood of detecting rare targets when they are present. This pattern holds particular importance in high-stakes visual search contexts. As an example, 20 to 30 percent of cancers are missed in radiological screenings due to the perceptual challenge of finding low prevalence abnormalities. While the LPE is well documented in adults, little is known about whether young children demonstrate similar prevalence-related search difficulties. Prior developmental research suggests that young children may distribute attention more broadly than adults, including task-irrelevant information. This global attentional style raises the possibility that children may show reduced susceptibility to the LPE. The present study is the first to empirically test this question using an eye-tracking visual search task with 4- to 5-year-old children compared to adults. Results indicated that both children and adults demonstrated the LPE, evidenced by reduced accuracy during low-prevalence target-present trials. Target-absent accuracy remained consistently high across prevalence levels. Children's search times were slower than adults, but age group did not account for the prevalence-related accuracy effect. These findings challenge the idea that young children are immune to the LPE and suggest that low target prevalence can influence visual search performance early in development. This study extends LPE research to younger populations, offering an expanded cognitive developmental perspective and highlighting the need for continued research on children's visual attention in real-world search contexts.