When do infants expect hands to be connected to a person?

A violation-of expectation paradigm was used to test whether infants infer a person based on the presence of hands alone Infants were familiarized to a pair of hands that extended out from a curtain to play with a rattle after which the curtain was opened to reveal either a real person or a mannequin Infants looking at these outcomes was compared with baseline looking at the person and the mannequin Experiment 1 showed that 9-month olds looked significantly longer at the mannequin than at the person after familiarization to hands Experiment 2 ruled out a low-level feature matching interpretation by showing the same looking pattern in 9 month olds even when the hands were covered with silver gloves In Experiment 3 6-month-olds showed no differential looking at the mannequin and person after familiarization to hands Taken together these experiments suggest that infants acquire the expectation that hands are connected to a person between 6 and 9 months of age This finding has implications for how infants attribute goals to manual actions (C) 2010 Elsevier Inc All rights reserved