Developmental tasks are skills and competencies that individuals are expected to achieve during certain periods of life according to their developmental stage. Examples of developmental tasks include learning to walk for infants, attending school for children ages 6 to 12, undergoing puberty from ages 10 to 14, and establishing independence during adolescence from ages 12 to 18. Successfully completing developmental tasks at each stage leads to happiness and prepares an individual for future tasks, while failure can result in unhappiness and difficulties with later development.