Explicitly attributing false beliefs leads to altercentric biases in preschool children's search for objects

Humans are influenced by the beliefs of others, even when irrelevant to their current tasks. Such altercentric biases have been observed both in adults and infants. Their developmental trajectory and relation to explicit belief reasoning, however, are unclear. We investigated how altercentric biases develop as children begin to explicitly reason about beliefs at 3-5 years (N=115, F=62, M=53, primarily White). Only children who passed standard false belief tasks, showed altercentric biases when searching for an object in a sandbox that another agent believed to be elsewhere. These biases were only present when children had previously explicitly reasoned about false beliefs. This suggests that altercentric biases may re-emerge in the preschool years, where they depend on explicit belief reasoning.