Piaget noted that children's thinking changes significantly during the concrete operations stage. They can engage in classification, which is the ability to group according to features, and serial ordering, which is the ability to group according to logical progression. Older children come to understand cause‐and‐effect relationships, so they become adept at mathematics and science. They also comprehend the concept of stable identity—that “self” remains constant even when circumstances change. For example, older children know that their father maintains a male identity regardless of what he wears or how old he becomes.
In Piaget's view, children at the beginning of concrete operations do demonstrate conservation. Unlike preschoolers, school‐age children understand that the same amount of clay molded into different shapes remains the same. Children in concrete operations have also advanced beyond the egocentrism of preschoolers. By the school years, children have usually learned that other people have their own views, feelings, and desires.