Five-month-old infants have different expectations for solids and liquids.
Many studies have established that 2-month-old infants have knowledge of solid objects' basic physical properties. Evidence about infants' understanding of nonsolid substances, however, is relatively sparse and equivocal. We present two experiments demonstrating that 5-month-old infants have distinct expectations for how solids and liquids behave. Experiment 1 showed that infants use the motion cues from the surface of a contained liquid or solid to predict whether it will pour or tumble from a cup if the cup is upended. Experiment 2 extended these findings to show that motion cues lead to distinct expectations about whether a new object will pass through or remain on top of a substance. Together, these experiments demonstrate that 5-month-old infants are able to use movement cues and solidity to discriminate a liquid from an object of similar appearance, providing the earliest evidence that infants can reason about nonsolid substances.
Psychology Department, Northwestern University, USA. hespos@northwestern.edu
Susan J
SJ
Hespos
Alissa L
AL
Ferry
Lance J
LJ
Rips
D001288:Attention; D003210:Concept Formation; D003463:Cues; D004192:Discrimination, Psychological; D005260:Female; D006185:Habituation, Psychophysiologic; D006801:Humans; D007223:Infant; D008297:Male; D009039:Motion Perception; D009949:Orientation; D010364:Pattern Recognition, Visual; D002666:Psychology, Child; D012718:Set, Psychology