Inferring hidden objects from still and communicative onlookers at 8, 14, and 36 months of age.

The current study investigated across five eye-tracking experiments children's developing skill of adopting others' referential perspective (Level 1 perspective taking) and to what extent it involves automatic processes or requires ostensive communicative cues. Three age groups (8-, 14-, and 36-month-olds) were tested on their expectation of an object appearing behind one of two peripheral occluders. A centrally presented person in profile either provided an ostensive communicative pointing cue or sat still, oriented to one of the two occluders. The 14-month-olds anticipated the hidden object when the onlooker had communicatively pointed to the location, as revealed by faster target detection in congruent trials (latency effect) and longer dwell times to the empty side in incongruent trials (violation-of-expectation effect). This was not the case when a still person was only oriented to one side. Adding emotional expressions to the still person (Experiment 2) did not help to produce the effects. However, at 36 months of age (Experiment 3), children showed both effects for the still person. The 8-month-olds did not show the violation-of-expectation effect for communicative pointing (Experiment 4) or for a matched abbreviated reach (Experiment 5b), showing it only for a complete reach behind the occluder (Experiment 5a), although they were faster to detect the congruent object in Experiment 4 and 5a. Findings reveal that automatic perspective taking develops after communicative perspective taking and that communicative perspective taking is a developmental outcome of the first year of life. The developmental pattern suggests a continuous social construction process of perspective-taking skills.

The development of gaze following in monolingual and bilingual infants: A multi-laboratory study.

Determining the meanings of words requires language learners to attend to what other people say. However, it behooves a young language learner to simultaneously encode relevant non-verbal cues, for example, by following the direction of their eye gaze. Sensitivity to cues such as eye gaze might be particularly important for bilingual infants, as they encounter less consistency between words and objects than monolingual infants, and do not always have access to the same word-learning heuristics (e.g., mutual exclusivity). In a preregistered study, we tested the hypothesis that bilingual experience would lead to a more pronounced ability to follow another's gaze. We used a gaze-following paradigm developed by Senju and Csibra (Current Biology, 18, 2008, 668) to test a total of 93 6- to 9-month-old and 229 12- to 15-month-old monolingual and bilingual infants, in 11 laboratories located in 8 countries. Monolingual and bilingual infants showed similar gaze-following abilities, and both groups showed age-related improvements in speed, accuracy, frequency, and duration of fixations to congruent objects. Unexpectedly, bilinguals tended to make more frequent fixations to on-screen objects, whether or not they were cued by the actor. These results suggest that gaze sensitivity is a fundamental aspect of development that is robust to variation in language exposure.