Development is an important aspect to how and why children learn. Children pass through several stages before becoming adults. There are four stages of growth where children learn certain things: infancy (birth to age two), early childhood (ages 3 to 8), later childhood (ages 9 to 12), and adolescence (ages 13 to 18) (Borgen, W. & Norman, E.). For teachers to effectively teach and understand students, the need to identify developmental behavior is a necessity. Adolescence is the beginning of a more complex thinking process. Since this age group encompasses those from the ages of thirteen to eighteen, teens in this developmental phase experience a variety of behavioral changes. The Adolescent Assessment textbook mentions that in cognitive development, "thinking changes both quantitatively and qualitatively during adolescence. Adolescents can think faster and more efficiently than children" (Gumbiner, 2003, p.27). Typical cognitive behaviors that adolescent youth encounter are: developing advanced reasoning skills, developing abstract thinking skills, and developing the ability to think about thinking (Novella, R.). Advanced reasoning skills involve answering the question, "what if?" This skill includes thinking about multiple options and possibilities. The use of more hypothetical and logical thinking skills are used to process information. Abstract thinking is the use of thinking about things that do not actually exist. Prime examples of this type of thinking skill would be religion, faith, or trust. The development of the ability to think about thinking is a process known as meta-cognition. As defined by Webster's dictionary, meta-cognition is "the awareness or analysis of one's own learning or thinking process." This thinking strategy can be used to improve learning, and an example of this development strategy would be creating mnemonic devices. Cognitive development changes can affect teens in a number of ways. One affect is that teens demonstrate a heightened level of self consciousness. Teens tend to believe that everyone is as concerned with their thoughts and behaviors as they are. Teens also tend to believe that no one has ever experienced the same feelings or emotions as they have. The coined phrase "drama queen" comes to mind in regard to this statement. In adolescent youth, often heard phrases are, "You'll never understand," or "You have ruined my life." Another typical cognitive behavior in the adolescent youth is the, "It can't happen to me" or the, "I'm invincible" syndrome. Teens often use this belief to make risks like drinking and driving, smoking, or other harmful and thoughtless behavioral decisions, without thinking of the consequences. Cognitive behaviors such as the tendency to become overly cause-oriented and to exhibit a "justice" orientation are also very present in adolescent development. An example of cause-oriented behavior would be a teen becoming vegetarian after reading about cruelty to animals. Justice oriented behavior is the tendency of teens to point out flaws between adults' words and their actions. Teens may confront their parents by saying something like, "But you let Johnny (big brother) go to the prom when he was a sophomore." They see little room for error and view points are seen more in black and white, rather than gray.