All the mental activities associated withthinking, knowing, remembering, and communicating. Believed that a child"s mind develops through a series of stages. Core idea is that the driving force behind our intellectual progression is an unceasing struggle to make sense of our experiences. A concept or framework that organizes and interprets information. Interpreting our new experiences in terms of our existing schemas. Adapting our current understandings (schemas) to incorporate new information. The stage (from birth-2 years) during which infants know the world mostly in terms of their sensory impressions and motor activities. Young infants lack object permanence (before 8 months) The awareness that things continue to exist even when not perceived. The fear of strangers that infants commonly display, beginning at about 8 months: preoperational stage. The stage (from about 2 years to 6-7 years) during which a child learns to use language but does not yet comprehend the mental operations of concrete logic.