Eight-Year-Old James Is Told to Look at Two Equal Amounts

Short Answer

Eight-year-old James is told to look at two equal amounts of juice in two identical glasses. Then, right in front of him, one of the glasses of juice is poured into a tall, skinny glass. James is convinced that the juice in the tall, skinny glass is more than the juice in the original glass. According to Piaget, James does not yet understand the concept of _____.