1. Abstract thinking is the ability to think about concepts, objects, and ideas that are not physically present using symbolic representation. It involves conceptualizing, shifting perspectives, grouping essentials and parts of a whole, and planning ahead. 2. Tests of abstract thinking include proverb interpretation, identifying similarities and differences between objects/situations, and completing conceptual series that require logical reasoning. 3. Formal operational thinking emerges in adolescence and is characterized by abstract thought, deductive reasoning, and defining concepts symbolically.