Evidence for a Low Number Prior in Children's Intuitive Number Sense

Children rely on their Approximate Number System to intuitively perceive number. Such adaptations often exhibit sensitivity to real-world statistics. This study investigates a potential manifestation of the ANS's sensitivity to real-world statistics: a negative power-law distribution of objects in natural scenes should be reflected in children's expectations about number, or in more Bayesian terms, a low number prior distribution. Five- to eight-year-old children (n = 80; 39 girls, 41 boys) and adults (n = 20) in 2022 completed a number discrimination task in which one side was corrupted by perceptual noise. Children and adults demonstrate a low number prior. No age-related differences were observed, suggesting that the prior is formed by age five and does not strengthen with age.