Final answer:
Formal operational thought is Piaget's term for the stage of cognitive development where individuals can use abstract thinking to approach hypothetical situations and engage in deductive reasoning. It is the fourth stage in Piaget's theory, starting around age 11.
Step-by-step explanation:
Formal, logical, hypothetical-deductive thinking described by Piaget is referred to as formal operational thought. This involves the ability to think abstractly and to deal with hypothetical situations, which becomes evident during adolescence. In Piaget's theory, this type of reasoning is characteristic of the fourth stage of cognitive development, beginning around age 11.
Deductive reasoning is associated with hypothesis-based science, where general principles are used to predict specific outcomes. For example, if scientists know that increased temperatures can affect biodiversity, they can predict changes in the distribution of plants and animals due to climate change. Piaget's formal operational thought includes this type of logical reasoning, wherein adolescents can apply hypothetical constructs and deduce implications.