Children become increasingly competent at adult-style thinking features of the development of memory in preschool age the “tween” years. Around the age of 11 or 12, children learn to think about abstract concepts. They complete what Piaget termed the concrete operational period and enter the formal operation period. During the formal operations period, which continues into adulthood, children develop logical thought, deductive reasoning abilities, and improved memory and executive function skills.
While not all people, and not all cultures, achieve formal operations, children become increasingly competent at adult-style thinking as they advance. Children this age are able to demonstrate abstract thinking. For example, they can understand shades of gray, wrestle with abstract concepts like love or justice, and formulate values based on thinking and analyzing as opposed to only by feeling or experiencing. They are able to classify items by many different features, such as organizing books by height while also grouping them by topic. During the early teen years, adolescent egocentrism emerges.