Who am I, how should I act, what is happening to my body? These are all questions that teenagers ask themselves. Adolescence is a critical time in cognitive development. This is the time between childhood and adulthood. The body and brain are undergoing changes that affect psychic growth and the psychological thought process. New experiences, new possibilities and new demands are placed on adolescents. How adolescents perceive themselves and the changes around them will influence their decision making. All adults have gone through adolescence and have had to experience this fascinating yet confusing period in human development. A human being's past experiences, health, gender, relationships they have had, the society they live in, their spiritual beliefs, and the emotional foundations that have been laid all play a role in how an individual will perceive , will process and make decisions. .There are many theories about human development. We have Vygotsky's cognitive theory, Freud's psychoanalytic theory and Erikson's theory of psychosocial development, Piaget's theory of cognitive development, Skinner's theory of operant conditioning, Bandura's social cognitive theory and many others. While many theories exist, most agree that humans go through stages of development. Each stage has important foundational developments that must be met in order to effectively progress to the next stage. Psychic, hormonal and mental changes occur as we progress through these stages. When making a decision there are two types of theories, the descriptive one, which studies the way in which most people make a decision, and the normative one, which indicates how a decision should be made to obtain the best results. There... in the middle of the paper. .....they become more independent and better decision makers. As they mature and their brains become more developed, they develop better psychological processes and improve their ability to think more logically. As adolescents become adults, they will be able to draw from their past experiences, relationships, beliefs, and knowledge of how the world works to improve their perception of themselves and better understand the processes needed to make decisions valid. Works Cited1) Santrock, J.W. (2012). A topical approach to development across the life span (6th ed.). New York, NY: McGraw-Hill.2) Mossler, Ronald (2011). Child and adolescent development. San Diego, CA: Bridgepoint Education, Inc., Retrieved from https://content.ashford.edu/books/AUPSY104.11.2/sections/copy3) Tada, J. (2014). Belgian euthanasia law does not protect children from themselves. Time. com, 1.