Juan and his little sister, anne, are each given a large cookie. their mother breaks anne's cookie into four pieces to enable her to eat it easily. juan immediately begins to cry and says that it is not fair for his sister to get so many cookies when he only has one. juan is showing a lack of:

Juan is showing a lack of conservation.

Conservation is a concept that is part of Piaget's theory of cognitive development. Conservation refers to the ability to realize that the quantity or amount of an object does not change despite its arrangement or physical appearance. In this instance, Juan lacks the ability of conservation since he perceives the four pieces of Anne's cookie as being greater in quantity that his intact cookie.