Final answer:
Individuals usually begin to demonstrate abstract thinking during adolescence, which aligns with the formal operational stage of Jean Piaget's cognitive development theory, beginning around age 11.
Step-by-step explanation:
Individuals typically demonstrate the ability to engage in abstract thinking, such as logic, deductive reasoning, comparison, and classification during adolescence. This stage of cognitive development corresponds to Jean Piaget's formal operational stage, which begins around age 11 and continues into adulthood. At this stage, adolescents are capable of thinking logically about abstract concepts, understanding hypothetical situations, and reasoning about ideas that do not have a physical presence.
Adolescent cognitive development includes processing complex concepts such as addition, subtraction, and cause-and-effect relationships. They begin to question authority and established norms, developing their own ideas and values. With the maturing of cognitive functions, teenagers improve in their problem-solving skills and their ability to plan and build structures, reflecting their more advanced cognitive abilities.
The development of cognitive skills such as postformal thinking is suggested to continue into early adulthood, integrating logic with emotion and making decisions based on context. It should be noted that there are differing views on the continuity of cognitive development, with some suggesting an additional postformal stage beyond adolescence.