This document discusses cognitive development in high school learners. It covers Piaget's theory of formal operational stage of cognitive development occurring from ages 12 to adulthood. Key aspects of formal thinking include hypothetical deductive reasoning, problem solving, and metacognition. The document also discusses brain development during adolescence, Siegler's information processing model, characteristics of overachievers and underachievers, parental involvement, adolescent behaviors, developing occupational skills using Holland's codes, and benefits of extracurricular activities.