Does communication-based belief attribution in 18-month-olds reflect an altercentric bias?

To successfully navigate the social world, young children may need to understand how others form beliefs and how these beliefs guide their behavior. While most studies targeted infants' tracking of others' beliefs based on visual access, it is unclear whether they can track communication-based beliefs. Here, we investigate 18-month-olds' understanding of others' beliefs induced via communication (Experiment 1: N = 34; Experiment 2 - replication: N = 35) through measuring their spontaneous pointing in a false-belief scenario. Infants' pointing was influenced by an agent's false-belief, revealing an unexpected altercentric effect: they pointed more to an object's initial location when the agent falsely believed the object to be there, compared to when she had a true belief. In Experiment 3 (N = 35), a similar effect was observed when the agent's belief was visually induced. Experiment 4 (N = 34) investigated whether the agent's false belief affects infants' memory. After infants' spontaneous pointing, a direct question about the object's location was asked. Infants were unlikely to switch their pointing from the initial location, revealing a potential altercentric memory bias. Experiment 5 (N = 28) targeted this effect more directly, exposing infants to a direct question only. Infants searched more in the initial location in the false belief condition. These results indicate that 18-month-olds' communicative pointing and memory about objects' locations are influenced by others' beliefs. The observed altercentric effects suggest that infants may spontaneously sustain others' beliefs in parallel with their own representations, both affecting their behaviors.