What do infants know about continuous quantity?

We investigated infants' sensitivity to amount of continuous quantity and t o change in amount of continuous quantity. Using a habituation procedure, E xperiment 1 examined whether 6-month-old infants can distinguish between di fferent amounts of, liquid in a container. Infants looked significantly lon ger at a novel quantity than at the familiar quantity. Using a violation-of -expectation paradigm, Experiment 2 examined whether 9-month-old infants ex pect a change in amount when liquid is added to a hidden container which is already one-fourth full of liquid. Infants looked significantly longer at the impossible event than at the possible event. These findings indicate th at infants are sensitive to amount, calling into question claims that infan ts have a quantitative mechanism which is exclusive to number. (C) 2000 Aca demic Press.